So Google tightening the look but don't touch approach? Not a surprise at all. Google already implement this approach with Push notifications (FCM/GCM) and Hardware Attestation that makes custom android OS/ROM harder to recommend for most people that need for example app that needs good Location service and Phone Payment like Google Wallet.
Just to be clear: Android is NOT becoming closed source! Google remains committed to releasing Android source code (during monthly/quarterly releases, etc.) , BUT you won't be able to scour the AOSP Gerrit for source code changes like you could before.
Big platforms will aggressively sabotage any country who tries taking their malwares from the population: better to go scorched-earth than to TOLERATE alternative/competition, right?
I won't be surprised when entire-countries' devices are bricked to teach the country a lesson, while the Russia+Trump alliance begins their total-war on that country..
Countries have already accommodated allowing all critical-infrastructure to be proprietary, in tech..
they are owned, & cannot get out of that with the incompetence that they got into it, with..
Exactly as the tech-oligarchs intended.
I'm a geek, & it makes me want to puke, what's been accomplished, against humankind's viability, by tech-people..
Contributing to AOSP is already difficult. Now patches wrt stable branch will lead to more conflicts as stable gets older.
Why are parts of Android developed in private?
It typically takes more than a year to bring a device to market. And, of course, device manufacturers want to ship the latest software they can. Meanwhile, developers don't want to constantly track new versions of the platform when writing apps. Both groups experience a tension between shipping products and not wanting to fall behind.