Debate fuels my Fire
There actually is, Mike Mearls specifically mentioned on a stream once that they have a book or binder somewhere that keeps track of everything important that needs to be considered canon, that they return to often when writing for FR.It's not just a matter of taste though. It's a matter of fact. There is no one at WotC keeping track of some "canon" version of FR. They are quite happy to allow the publication of stories and adventures that make contradictory assumptions about earlier events, and they are all equally true/not true.
That said, just because that is true doesn't mean they aren't open to changing things if it contradicts canon. Clearly "is it fun" matters more to their writers than "is it canon," like the changing of the first archdevil being Zariel instead of Bel.