It doesn’t have to do anything, but if it doesn’t support what are considered standard features of a phone today in an open manner, it’s hard to take AOSP seriously as an open platform.
Also worth noting that when someone does build on top of AOSP, they are at the mercy of Google’s roadmap for the closed versions of Android.
Also worth noting that when someone does build on top of AOSP, they are at the mercy of Google’s roadmap for the closed versions of Android.