You're assuming Flutter has buy-in from the Androidd team. Nothing shows that's true though.
I think it is more management having fun and watching which dog fights better, what Android team thinks is less relevant.
Jetpack Composer is obviously they fighting back to the continuous flow of Flutter questions at Android conferences.
Android is going the way of Google Reader. Kotlin is just to keep developers happy in the meantime before explicit deprecation. Fuchsia + Flutter is the new platform. Android Runtime will be emulated to allow backward compatible Android apps at a performance penalty, but Fuchsia will only have first class support for native compiled languages like Dart, Go, C++, Swift, similar to iOS.
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