diff --git a/addons/mrp_subcontracting/__manifest__.py b/addons/mrp_subcontracting/__manifest__.py
index 5af0dfc8794..baf4fb86f08 100644
--- a/addons/mrp_subcontracting/__manifest__.py
+++ b/addons/mrp_subcontracting/__manifest__.py
@@ -107,7 +107,6 @@
             'web/static/src/legacy/js/core/ajax.js',
             'web/static/src/legacy/js/core/bus.js',
             'web/static/src/legacy/js/core/class.js',
-            'web/static/src/legacy/js/core/concurrency.js',
             'web/static/src/legacy/js/core/dialog.js',
             'web/static/src/legacy/xml/dialog.xml',
             'web/static/src/legacy/js/core/dom.js',
diff --git a/addons/point_of_sale/__manifest__.py b/addons/point_of_sale/__manifest__.py
index dc257942f68..45c3be7829d 100644
--- a/addons/point_of_sale/__manifest__.py
+++ b/addons/point_of_sale/__manifest__.py
@@ -142,7 +142,6 @@
             # FIXME POSREF legacy dependencies to remove
             'web/static/lib/moment/moment.js',
             'web/static/src/legacy/js/promise_extension.js',
-            'web/static/src/legacy/js/core/concurrency.js',
             'web/static/src/legacy/legacy_component.js',
         ],
         # Bundle that starts the pos, loaded on /pos/ui
diff --git a/addons/pos_loyalty/static/src/overrides/models/loyalty.js b/addons/pos_loyalty/static/src/overrides/models/loyalty.js
index 98d843405be..6d60692bb8b 100644
--- a/addons/pos_loyalty/static/src/overrides/models/loyalty.js
+++ b/addons/pos_loyalty/static/src/overrides/models/loyalty.js
@@ -2,17 +2,13 @@
 
 import { Order, Orderline } from "@point_of_sale/app/store/models";
 import { Mutex } from "@web/core/utils/concurrency";
-import concurrency from "@web/legacy/js/core/concurrency";
 import { roundDecimals, roundPrecision } from "@web/core/utils/numbers";
 import { _t } from "@web/core/l10n/translation";
 import { patch } from "@web/core/utils/patch";
 import { ConfirmPopup } from "@point_of_sale/app/utils/confirm_popup/confirm_popup";
 
-// FIXME: Perhaps MutexedDropPrevious can be replaced by the new KeepLast.
-// > This might require thorough investigation on how _updateRewards work.
-// > If successful, we can fully get rid of the legacy concurrency module.
-const dropPrevious = new concurrency.MutexedDropPrevious(); // Used for queuing reward updates
 const mutex = new Mutex(); // Used for sequential cache updates
+const updateRewardsMutex = new Mutex();
 
 function _newRandomRewardCode() {
     return (Math.random() + 1).toString(36).substring(3);
@@ -150,9 +146,9 @@ patch(Order.prototype, {
 
     /** @override */
     getEmailItems() {
-        return super.getEmailItems(...arguments).concat(
-            this.has_pdf_gift_card ? [_t("the gift cards")] : []
-        );
+        return super
+            .getEmailItems(...arguments)
+            .concat(this.has_pdf_gift_card ? [_t("the gift cards")] : []);
     },
 
     export_as_JSON() {
@@ -300,15 +296,18 @@ patch(Order.prototype, {
         return orderLines[orderLines.length - 1];
     },
     set_pricelist(pricelist) {
-        const oldPricelist = this.pricelist
+        const oldPricelist = this.pricelist;
         super.set_pricelist(...arguments);
         if (this.couponPointChanges && oldPricelist !== pricelist) {
             // Remove couponPointChanges for cards in no longer available programs.
             // This makes sure that counting of points on loyalty and ewallet programs is updated after pricelist changes.
             const loyaltyProgramIds = new Set(
                 this.pos.programs
-                    .filter((program) => program.pricelist_ids.length > 0
-                        && (!pricelist || !program.pricelist_ids.includes(pricelist.id)))
+                    .filter(
+                        (program) =>
+                            program.pricelist_ids.length > 0 &&
+                            (!pricelist || !program.pricelist_ids.includes(pricelist.id))
+                    )
                     .map((program) => program.id)
             );
             for (const [key, pointChange] of Object.entries(this.couponPointChanges)) {
@@ -367,33 +366,30 @@ patch(Order.prototype, {
         if (this.pos.programs.length === 0) {
             return;
         }
-        dropPrevious
-            .exec(() => {
-                return this._updateLoyaltyPrograms().then(async () => {
-                    // Try auto claiming rewards
-                    const claimableRewards = this.getClaimableRewards(false, false, true);
-                    let changed = false;
-                    for (const { coupon_id, reward } of claimableRewards) {
-                        if (
-                            reward.program_id.rewards.length === 1 &&
-                            !reward.program_id.is_nominative &&
-                            (reward.reward_type !== "product" ||
-                                (reward.reward_type == "product" && !reward.multi_product))
-                        ) {
-                            this._applyReward(reward, coupon_id);
-                            changed = true;
-                        }
+
+        updateRewardsMutex.exec(() => {
+            return this._updateLoyaltyPrograms().then(async () => {
+                // Try auto claiming rewards
+                const claimableRewards = this.getClaimableRewards(false, false, true);
+                let changed = false;
+                for (const { coupon_id, reward } of claimableRewards) {
+                    if (
+                        reward.program_id.rewards.length === 1 &&
+                        !reward.program_id.is_nominative &&
+                        (reward.reward_type !== "product" ||
+                            (reward.reward_type == "product" && !reward.multi_product))
+                    ) {
+                        this._applyReward(reward, coupon_id);
+                        changed = true;
                     }
-                    // Rewards may impact the number of points gained
-                    if (changed) {
-                        await this._updateLoyaltyPrograms();
-                    }
-                    this._updateRewardLines();
-                });
-            })
-            .catch(() => {
-                /* catch the reject of dp when calling `add` to avoid unhandledrejection */
+                }
+                // Rewards may impact the number of points gained
+                if (changed) {
+                    await this._updateLoyaltyPrograms();
+                }
+                this._updateRewardLines();
             });
+        });
     },
     async _updateLoyaltyPrograms() {
         await this._checkMissingCoupons();
@@ -716,7 +712,10 @@ patch(Order.prototype, {
         if (program.limit_usage && program.total_order_count >= program.max_usage) {
             return false;
         }
-        if (program.pricelist_ids.length > 0 && (!this.pricelist || !program.pricelist_ids.includes(this.pricelist.id))) {
+        if (
+            program.pricelist_ids.length > 0 &&
+            (!this.pricelist || !program.pricelist_ids.includes(this.pricelist.id))
+        ) {
             return false;
         }
         return true;
@@ -949,8 +948,10 @@ patch(Order.prototype, {
             : 0;
         for (const couponProgram of allCouponPrograms) {
             const program = this.pos.program_by_id[couponProgram.program_id];
-            if (program.pricelist_ids.length > 0
-                && (!this.pricelist || !program.pricelist_ids.includes(this.pricelist.id))) {
+            if (
+                program.pricelist_ids.length > 0 &&
+                (!this.pricelist || !program.pricelist_ids.includes(this.pricelist.id))
+            ) {
                 continue;
             }
             if (program.trigger == "with_code") {
@@ -1165,7 +1166,7 @@ patch(Order.prototype, {
         let cheapestLine = false;
         for (const lines of Object.values(discountLinesPerReward)) {
             const lineReward = this.pos.reward_by_id[lines[0].reward_id];
-            if (lineReward.reward_type !== 'discount') {
+            if (lineReward.reward_type !== "discount") {
                 continue;
             }
             let discountedLines = orderLines;
@@ -1496,9 +1497,11 @@ patch(Order.prototype, {
         let claimableRewards = null;
         let coupon = null;
         if (rule) {
-            let program_pricelists = rule.program_id.pricelist_ids;
-            if (program_pricelists.length > 0
-                && (!this.pricelist || !program_pricelists.includes(this.pricelist.id))) {
+            const program_pricelists = rule.program_id.pricelist_ids;
+            if (
+                program_pricelists.length > 0 &&
+                (!this.pricelist || !program_pricelists.includes(this.pricelist.id))
+            ) {
                 return _t("That promo code program requires a specific pricelist.");
             }
             if (this.codeActivatedProgramRules.includes(rule.id)) {
@@ -1515,7 +1518,13 @@ patch(Order.prototype, {
             const { successful, payload } = await this.env.services.orm.call(
                 "pos.config",
                 "use_coupon_code",
-                [[this.pos.config.id], code, this.creation_date, customerId, this.pricelist ? this.pricelist.id : false]
+                [
+                    [this.pos.config.id],
+                    code,
+                    this.creation_date,
+                    customerId,
+                    this.pricelist ? this.pricelist.id : false,
+                ]
             );
             if (successful) {
                 // Allow rejecting a gift card that is not yet paid.
diff --git a/addons/project/__manifest__.py b/addons/project/__manifest__.py
index 4d0d5e7638e..c8bc23d2ceb 100644
--- a/addons/project/__manifest__.py
+++ b/addons/project/__manifest__.py
@@ -158,7 +158,6 @@
             'web/static/src/legacy/js/core/ajax.js',
             'web/static/src/legacy/js/core/bus.js',
             'web/static/src/legacy/js/core/class.js',
-            'web/static/src/legacy/js/core/concurrency.js',
             'web/static/src/legacy/js/core/dialog.js',
             'web/static/src/legacy/xml/dialog.xml',
             'web/static/src/legacy/js/core/dom.js',
diff --git a/addons/web/__manifest__.py b/addons/web/__manifest__.py
index cc459f304f2..e83395003d7 100644
--- a/addons/web/__manifest__.py
+++ b/addons/web/__manifest__.py
@@ -107,7 +107,6 @@ This module provides the core of the Odoo Web Client.
             'web/static/src/legacy/js/core/ajax.js',
             'web/static/src/legacy/js/core/bus.js',
             'web/static/src/legacy/js/core/class.js',
-            'web/static/src/legacy/js/core/concurrency.js',
             'web/static/src/legacy/js/core/dialog.js',
             'web/static/src/legacy/xml/dialog.xml',
             'web/static/src/legacy/js/core/dom.js',
@@ -265,7 +264,6 @@ This module provides the core of the Odoo Web Client.
             'web/static/src/legacy/js/core/ajax.js',
             'web/static/src/legacy/js/core/bus.js',
             'web/static/src/legacy/js/core/class.js',
-            'web/static/src/legacy/js/core/concurrency.js',
             'web/static/src/legacy/js/core/dialog.js',
             'web/static/src/legacy/xml/dialog.xml',
             'web/static/src/legacy/js/core/dom.js',
diff --git a/addons/web/static/src/legacy/js/core/concurrency.js b/addons/web/static/src/legacy/js/core/concurrency.js
deleted file mode 100644
index 7626dfe2524..00000000000
--- a/addons/web/static/src/legacy/js/core/concurrency.js
+++ /dev/null
@@ -1,109 +0,0 @@
-/** @odoo-module **/
-
-/**
- * Concurrency Utils
- *
- * This file contains a short collection of useful helpers designed to help with
- * everything concurrency related in Odoo.
- *
- * The basic concurrency primitives in Odoo JS are the callback, and the
- * promises.  Promises (promise) are more composable, so we usually use them
- * whenever possible.  We use the jQuery implementation.
- *
- * Those functions are really nothing special, but are simply the result of how
- * we solved some concurrency issues, when we noticed that a pattern emerged.
- */
-
-import Class from "@web/legacy/js/core/class";
-
-const concurrency = {
-    /**
-     * A MutexedDropPrevious is a primitive for serializing computations while
-     * skipping the ones that where executed between a current one and before
-     * the execution of a new one. This is useful to avoid useless RPCs.
-     *
-     * You can read the Mutex description to understand its role ; for the
-     * DropPrevious part of this abstraction, imagine the following situation:
-     * you have a code that call the server with a fixed argument and a list of
-     * operations that only grows after each call and you only care about the
-     * RPC result (the server code doesn't do anything). If this code is called
-     * three times (A B C) and C is executed before B has started, it's useless
-     * to make an extra RPC (B) if you know that it won't have an impact and you
-     * won't use its result.
-     *
-     * Note that the promise returned by the exec call won't be resolved if
-     * exec is called before the first exec call resolution ; only the promise
-     * returned by the last exec call will be resolved (the other are rejected);
-     *
-     * A MutexedDropPrevious has to be a class, and not a function, because we
-     * have to keep track of some internal state. The exec function takes as
-     * argument an action (and not a promise as DropPrevious for example)
-     * because it's the MutexedDropPrevious role to trigger the RPC call that
-     * returns a promise when it's time.
-     */
-    MutexedDropPrevious: Class.extend({
-        init: function () {
-            this.locked = false;
-            this.currentProm = null;
-            this.pendingAction = null;
-            this.pendingProm = null;
-        },
-        /**
-         * @param {function} action a function which may return a promise
-         * @returns {Promise}
-         */
-        exec: function (action) {
-            var self = this;
-            var resolution;
-            var rejection;
-            if (this.locked) {
-                this.pendingAction = action;
-                var oldPendingDef = this.pendingProm;
-
-                this.pendingProm = new Promise(function (resolve, reject) {
-                    resolution = resolve;
-                    rejection = reject;
-                    if (oldPendingDef) {
-                        oldPendingDef.reject();
-                    }
-                    self.currentProm.reject();
-                });
-                this.pendingProm.resolve = resolution;
-                this.pendingProm.reject = rejection;
-                return this.pendingProm;
-            } else {
-                this.locked = true;
-                this.currentProm = new Promise(function (resolve, reject) {
-                    resolution = resolve;
-                    rejection = reject;
-                    function unlock() {
-                        self.locked = false;
-                        if (self.pendingAction) {
-                            var action = self.pendingAction;
-                            var prom = self.pendingProm;
-                            self.pendingAction = null;
-                            self.pendingProm = null;
-                            self.exec(action)
-                                .then(prom.resolve)
-                                .guardedCatch(prom.reject);
-                        }
-                    }
-                    Promise.resolve(action())
-                        .then(function (result) {
-                            resolve(result);
-                            unlock();
-                        })
-                        .guardedCatch(function (reason) {
-                            reject(reason);
-                            unlock();
-                        });
-                });
-                this.currentProm.resolve = resolution;
-                this.currentProm.reject = rejection;
-                return this.currentProm;
-            }
-        }
-    }),
-};
-
-export default concurrency;
diff --git a/addons/web/static/tests/legacy/core/concurrency_tests.js b/addons/web/static/tests/legacy/core/concurrency_tests.js
deleted file mode 100644
index 3d900643644..00000000000
--- a/addons/web/static/tests/legacy/core/concurrency_tests.js
+++ /dev/null
@@ -1,379 +0,0 @@
-/** @odoo-module **/
-
-import concurrency from "@web/legacy/js/core/concurrency";
-import { Mutex } from "@web/core/utils/concurrency";
-import testUtils from "@web/../tests/legacy/helpers/test_utils";
-
-var makeTestPromise = testUtils.makeTestPromise;
-var makeTestPromiseWithAssert = testUtils.makeTestPromiseWithAssert;
-
-QUnit.module('core', {}, function () {
-
-    QUnit.module('concurrency');
-
-    QUnit.test('mutex: simple scheduling', async function (assert) {
-        assert.expect(5);
-        var mutex = new Mutex();
-
-        var prom1 = makeTestPromiseWithAssert(assert, 'prom1');
-        var prom2 = makeTestPromiseWithAssert(assert, 'prom2');
-
-        mutex.exec(function () { return prom1; });
-        mutex.exec(function () { return prom2; });
-
-        assert.verifySteps([]);
-
-        await prom1.resolve();
-
-        assert.verifySteps(['ok prom1']);
-
-        await prom2.resolve();
-
-        assert.verifySteps(['ok prom2']);
-    });
-
-    QUnit.test('mutex: simpleScheduling2', async function (assert) {
-        assert.expect(5);
-        var mutex = new Mutex();
-
-        var prom1 = makeTestPromiseWithAssert(assert, 'prom1');
-        var prom2 = makeTestPromiseWithAssert(assert, 'prom2');
-
-        mutex.exec(function () { return prom1; });
-        mutex.exec(function () { return prom2; });
-
-        assert.verifySteps([]);
-
-        await prom2.resolve();
-
-        assert.verifySteps(['ok prom2']);
-
-        await prom1.resolve();
-
-        assert.verifySteps(['ok prom1']);
-    });
-
-    QUnit.test('mutex: reject', async function (assert) {
-        assert.expect(7);
-        var mutex = new Mutex();
-
-        var prom1 = makeTestPromiseWithAssert(assert, 'prom1');
-        var prom2 = makeTestPromiseWithAssert(assert, 'prom2');
-        var prom3 = makeTestPromiseWithAssert(assert, 'prom3');
-
-        mutex.exec(function () { return prom1; }).catch(function () {});
-        mutex.exec(function () { return prom2; }).catch(function () {});
-        mutex.exec(function () { return prom3; }).catch(function () {});
-
-        assert.verifySteps([]);
-
-        prom1.resolve();
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['ok prom1']);
-
-        prom2.catch(function () {
-           assert.verifySteps(['ko prom2']);
-        });
-        prom2.reject({name: "sdkjfmqsjdfmsjkdfkljsdq"});
-        await testUtils.nextMicrotaskTick();
-
-        prom3.resolve();
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['ok prom3']);
-    });
-
-    QUnit.test('mutex: getUnlockedDef checks', async function (assert) {
-        assert.expect(9);
-
-        var mutex = new Mutex();
-
-        var prom1 = makeTestPromiseWithAssert(assert, 'prom1');
-        var prom2 = makeTestPromiseWithAssert(assert, 'prom2');
-
-        mutex.getUnlockedDef().then(function () {
-            assert.step('mutex unlocked (1)');
-        });
-
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['mutex unlocked (1)']);
-
-        mutex.exec(function () { return prom1; });
-        await testUtils.nextMicrotaskTick();
-
-        mutex.getUnlockedDef().then(function () {
-            assert.step('mutex unlocked (2)');
-        });
-
-        assert.verifySteps([]);
-
-        mutex.exec(function () { return prom2; });
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps([]);
-
-        await prom1.resolve();
-
-        assert.verifySteps(['ok prom1']);
-
-        prom2.resolve();
-        await testUtils.nextTick();
-
-        assert.verifySteps(['ok prom2', 'mutex unlocked (2)']);
-    });
-
-    QUnit.test('mutex: error and getUnlockedDef', async function (assert) {
-        const mutex = new Mutex();
-        mutex.exec(async () => {
-            await Promise.resolve();
-            throw new Error("boom");
-        }).catch(() => assert.step("prom rejected"));
-        await testUtils.nextTick();
-        assert.verifySteps(['prom rejected']);
-
-        mutex.getUnlockedDef().then(function () {
-            assert.step('mutex unlocked');
-        });
-        await testUtils.nextMicrotaskTick();
-        assert.verifySteps(['mutex unlocked']);
-    });
-
-    QUnit.test('MutexedDropPrevious: simple', async function (assert) {
-        assert.expect(5);
-
-        var m = new concurrency.MutexedDropPrevious();
-        var d1 = makeTestPromise();
-
-        d1.then(function () {
-            assert.step("d1 resolved");
-        });
-        m.exec(function () { return d1; }).then(function (result) {
-            assert.step("p1 done");
-            assert.strictEqual(result, 'd1');
-        });
-
-        assert.verifySteps([]);
-        d1.resolve('d1');
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(["d1 resolved","p1 done"]);
-    });
-
-    QUnit.test('MutexedDropPrevious: d2 arrives after d1 resolution', async function (assert) {
-        assert.expect(8);
-
-        var m = new concurrency.MutexedDropPrevious();
-        var d1 = makeTestPromiseWithAssert(assert, 'd1');
-
-        m.exec(function () { return d1; }).then(function () {
-            assert.step("p1 resolved");
-        });
-
-        assert.verifySteps([]);
-        d1.resolve('d1');
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['ok d1','p1 resolved']);
-
-        var d2 = makeTestPromiseWithAssert(assert, 'd2');
-        m.exec(function () { return d2; }).then(function () {
-            assert.step("p2 resolved");
-        });
-
-        assert.verifySteps([]);
-        d2.resolve('d2');
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['ok d2','p2 resolved']);
-    });
-
-    QUnit.test('MutexedDropPrevious: p1 does not return a deferred', async function (assert) {
-        assert.expect(7);
-
-        var m = new concurrency.MutexedDropPrevious();
-
-        m.exec(function () { return 42; }).then(function () {
-            assert.step("p1 resolved");
-        });
-
-        assert.verifySteps([]);
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['p1 resolved']);
-
-        var d2 = makeTestPromiseWithAssert(assert, 'd2');
-        m.exec(function () { return d2; }).then(function () {
-            assert.step("p2 resolved");
-        });
-
-        assert.verifySteps([]);
-        d2.resolve('d2');
-        await testUtils.nextMicrotaskTick();
-        assert.verifySteps(['ok d2','p2 resolved']);
-    });
-
-    QUnit.test('MutexedDropPrevious: p2 arrives before p1 resolution', async function (assert) {
-        assert.expect(8);
-
-        var m = new concurrency.MutexedDropPrevious();
-        var d1 = makeTestPromiseWithAssert(assert, 'd1');
-
-        m.exec(function () { return d1; }).catch(function () {
-            assert.step("p1 rejected");
-        });
-        assert.verifySteps([]);
-
-        var d2 = makeTestPromiseWithAssert(assert, 'd2');
-        m.exec(function () { return d2; }).then(function () {
-            assert.step("p2 resolved");
-        });
-
-        assert.verifySteps([]);
-        d1.resolve('d1');
-        await testUtils.nextMicrotaskTick();
-        assert.verifySteps(['p1 rejected', 'ok d1']);
-
-        d2.resolve('d2');
-        await testUtils.nextMicrotaskTick();
-        assert.verifySteps(['ok d2', 'p2 resolved']);
-    });
-
-    QUnit.test('MutexedDropPrevious: 3 arrives before 2 initialization', async function (assert) {
-        assert.expect(10);
-        var m = new concurrency.MutexedDropPrevious();
-
-        var d1 = makeTestPromiseWithAssert(assert, 'd1');
-        var d3 = makeTestPromiseWithAssert(assert, 'd3');
-
-        m.exec(function () { return d1; }).catch(function () {
-            assert.step('p1 rejected');
-        });
-
-        m.exec(function () {
-            assert.ok(false, "should not execute this function");
-        }).catch(function () {
-            assert.step('p2 rejected');
-        });
-
-        m.exec(function () { return d3; }).then(function (result) {
-            assert.strictEqual(result, 'd3');
-            assert.step('p3 resolved');
-        });
-
-        assert.verifySteps([]);
-
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['p1 rejected', 'p2 rejected']);
-
-        d1.resolve('d1');
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['ok d1']);
-
-        d3.resolve('d3');
-        await testUtils.nextTick();
-
-
-        assert.verifySteps(['ok d3','p3 resolved']);
-    });
-
-    QUnit.test('MutexedDropPrevious: 3 arrives after 2 initialization', async function (assert) {
-        assert.expect(15);
-        var m = new concurrency.MutexedDropPrevious();
-
-        var d1 = makeTestPromiseWithAssert(assert, 'd1');
-        var d2 = makeTestPromiseWithAssert(assert, 'd2');
-        var d3 = makeTestPromiseWithAssert(assert, 'd3');
-
-        m.exec(function () {
-            assert.step('execute d1');
-            return d1;
-        }).catch(function () {
-            assert.step('p1 rejected');
-        });
-
-        m.exec(function () {
-            assert.step('execute d2');
-            return d2;
-        }).catch(function () {
-            assert.step('p2 rejected');
-        });
-
-        assert.verifySteps(['execute d1']);
-
-        await testUtils.nextMicrotaskTick();
-        assert.verifySteps(['p1 rejected']);
-
-        d1.resolve('d1');
-        await testUtils.nextMicrotaskTick();
-
-        assert.verifySteps(['ok d1', 'execute d2']);
-
-        m.exec(function () {
-            assert.step('execute d3');
-            return d3;
-        }).then(function () {
-            assert.step('p3 resolved');
-        });
-        await testUtils.nextMicrotaskTick();
-        assert.verifySteps(['p2 rejected']);
-
-        d2.resolve();
-        await testUtils.nextMicrotaskTick();
-        assert.verifySteps(['ok d2', 'execute d3']);
-
-        d3.resolve();
-        await testUtils.nextTick();
-        assert.verifySteps(['ok d3', 'p3 resolved']);
-
-     });
-
-    QUnit.test('MutexedDropPrevious: 2 in then of 1 with 3', async function (assert) {
-        assert.expect(9);
-
-        var m = new concurrency.MutexedDropPrevious();
-
-        var d1 = makeTestPromiseWithAssert(assert, 'd1');
-        var d2 = makeTestPromiseWithAssert(assert, 'd2');
-        var d3 = makeTestPromiseWithAssert(assert, 'd3');
-        var p3;
-
-        m.exec(function () { return d1; })
-            .catch(function () {
-                assert.step('p1 rejected');
-                p3 = m.exec(function () {
-                    return d3;
-                }).then(function () {
-                    assert.step('p3 resolved');
-                });
-                return p3;
-            });
-
-        await testUtils.nextTick();
-        assert.verifySteps([]);
-
-        m.exec(function () {
-            assert.ok(false, 'should not execute this function');
-            return d2;
-        }).catch(function () {
-            assert.step('p2 rejected');
-        });
-
-        await testUtils.nextTick();
-        assert.verifySteps(['p1 rejected', 'p2 rejected']);
-
-        d1.resolve('d1');
-        await testUtils.nextTick();
-
-        assert.verifySteps(['ok d1']);
-
-        d3.resolve('d3');
-        await testUtils.nextTick();
-
-        assert.verifySteps(['ok d3', 'p3 resolved']);
-    });
-
-});
diff --git a/addons/web_editor/__manifest__.py b/addons/web_editor/__manifest__.py
index 628a596d692..cc138b307fa 100644
--- a/addons/web_editor/__manifest__.py
+++ b/addons/web_editor/__manifest__.py
@@ -97,7 +97,6 @@ Odoo Web Editor widget.
             'web/static/src/legacy/js/core/ajax.js',
             'web/static/src/legacy/js/core/bus.js',
             'web/static/src/legacy/js/core/class.js',
-            'web/static/src/legacy/js/core/concurrency.js',
             'web/static/src/legacy/js/core/dialog.js',
             'web/static/src/legacy/xml/dialog.xml',
             'web/static/src/legacy/js/core/dom.js',
diff --git a/addons/website_slides/__manifest__.py b/addons/website_slides/__manifest__.py
index 2ba6cde8aba..c787dca21da 100644
--- a/addons/website_slides/__manifest__.py
+++ b/addons/website_slides/__manifest__.py
@@ -200,7 +200,6 @@ Featuring
             'web/static/src/legacy/js/core/ajax.js',
             'web/static/src/legacy/js/core/bus.js',
             'web/static/src/legacy/js/core/class.js',
-            'web/static/src/legacy/js/core/concurrency.js',
             'web/static/src/legacy/js/core/dialog.js',
             'web/static/src/legacy/xml/dialog.xml',
             'web/static/src/legacy/js/core/dom.js',