Google wants to continue working on the optimization of their update distribution and has already taken measures: Besides the Android Enterprise recommended certification, also the Project Treble is helping to streamline OS updates. Starting with Android Q, Project Mainline is added.
In Android Q, 14 modules were defined in which safety-relevant components were combined. These can be updated directly via Google Play, so they don`t have to be updated by the manufacturer. Under certain circumstances, the manufactorers can opt-out. Thanks to Project Treble, OS adaptations and updates must run on AOSP, thus serving as a basis for Project Mainline.
Google assures that the contents of the updates are still open source and will provide the code via AOSP.