Try to readd initializer

ember-can/package.json

@@ -121,6 +121,7 @@
     "app-js": {
       "./helpers/can.js": "./dist/_app_/helpers/can.js",
       "./helpers/cannot.js": "./dist/_app_/helpers/cannot.js",
+      "./initializers/setup-ember-can.js": "./dist/_app_/initializers/setup-ember-can.js",
       "./services/abilities.js": "./dist/_app_/services/abilities.js"
     }
   },

ember-can/rollup.config.mjs

@@ -21,6 +21,7 @@ export default {
     // is aligned to the config here.
     // See https://github.com/embroider-build/embroider/blob/main/docs/v2-faq.md#how-can-i-define-the-public-exports-of-my-addon
     addon.publicEntrypoints([
+      'initializers/**/*.js',
       'index.js',
       'resolver.js',
       'ability.ts',
@@ -31,7 +32,11 @@ export default {
     // These are the modules that should get reexported into the traditional
     // "app" tree. Things in here should also be in publicEntrypoints above, but
     // not everything in publicEntrypoints necessarily needs to go here.
-    addon.appReexports(['helpers/**/*.js', 'services/**/*.js']),
+    addon.appReexports([
+      'helpers/**/*.js',
+      'initializers/**/*.js',
+      'services/**/*.js',
+    ]),
 
     // Follow the V2 Addon rules about dependencies. Your code can import from
     // `dependencies` and `peerDependencies` as well as standard Ember-provided

ember-can/src/resolver.ts → ember-can/src/initializers/setup-ember-can.js

@@ -9,3 +9,6 @@ Resolver.reopen({
     };
   },
 });
+
+export function initialize() {}
+export default { initialize };

test-app/app/app.ts

@@ -2,7 +2,6 @@ import Application from '@ember/application';
 import Resolver from 'ember-resolver';
 import loadInitializers from 'ember-load-initializers';
 import config from 'test-app/config/environment';
-import 'ember-can/resolver';
 
 export default class App extends Application {
   modulePrefix = config.modulePrefix;