I have come across this post on Android:
The new app publishing format, the Android App Bundle, is an improved way to package your app. The Android App Bundle lets you more easily deliver a great experience in a smaller app size, allowing for the huge variety of Android devices available today. You don’t need to refactor your code to start benefiting from a smaller app.
Will this also be available on Xamarin soon?
I think it will be a very nice feature and useful!