The whole single A, triple A thing comes from league baseball. Single A was the lower leagues and AAA is the top of the heap pro ball. AAA denotes big budget tent pole productions. So big a studio could go bankrupt if it doesn't do well.
it's actually from credit ratings which predate baseball leagues
Ah so the OP thinks OBAA was designed as a big budget popcorn flick? No wonder they didn't like it.