For those wondering what happened, the Android Open Source Project (ASOP) launched in 2007, but started decoupling major parts of the project from the main in 2012 instead forcing them to update through Google Play store and over time restricting access to the codebase before just this year deciding to shut down the ASOP.
In their defence, they've also made lots of changes to make android compatible with more devices and to make third party stores work better, but they've just as often made changes that intentionally harmed development of alternative android-based OS.