[everyone]

ok, but even that is never used. For instance no publisher ever announces the release of their new "AA" or "A" game.

[TillE]

AA is absolutely being used in the gaming press, particularly to distinguish mid-sized decently-funded (eg, Kickstarter'd) studios from proper indie games.

I doubt you'll find many instances of "AAA" in press releases either. It's an industry term, not intended for the general public.