The issue: apps that are only updated with the OS end up outdated.
The current solution: Move them out of AOSP, into Google's internal projects, distribute updates via the Play Store.
An alternative solution: Move them out of AOSP, onto GitHub, distribute updates via the Play Store.
Yes, Google had to decouple them from AOSP. But that’s no reason not to put the code anywhere else in the open. These issues are entirely orthogonal, and Google uses it as a way to force more people onto the proprietary ones.