If Google actually cared, they would impose support requirements on OEMs that wanted to play on Android playground.
how authoritarian could Google be about forcing this on, say, Samsung?
and if they granted Samsung an exception, what would the reaction be from other manufacturers?
Given the results of Bada and Tizen, Google would have little to worry about if Samsung ever decides to go rogue.
OEMs are expected to push updates just like before, having a certified Treble device is meaningless, if the OEM does not care to provide OS updates.
If Google actually cared, they would impose support requirements on OEMs that wanted to play on Android playground.