Two Google teams talking to each other and syncing their agendas and deliveries (or two teams in any big company) is quite a major assumption.
It's also assuming that the Flutter team wouldn't consider do that considering they have that kind of information available to them -- it's in their best interest, after all.
I agree with the other commenter -- don’t expect any close cooperation between Flutter and Android because that’s just not how Google (and other huge companies) tends to work.