Android App Bundle Requirement

AAP is the coming way to have Android app distributed to Google Play store.

https://android-developers.googleblog.com/2021/06/the-future-of-android-app-bundles-is.html

If you currently get internal app distributed using apk, there is no change for you.

Please note that this new requirement is not mandatory for internal app. You can keep using apk per following KB

https://support.google.com/googleplay/work/answer/6145139