There's no such thing (parent likely borrowed this term from the video game industry)

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.

Ah so the OP thinks OBAA was designed as a big budget popcorn flick? No wonder they didn't like it.

Paul Thomas Anderson will tell anyone who will listen that he doesn't make commercially sound films. It's kind of his thing...

They did throw some serious money at this film, though, so I can see where people would have strange expectations.

it's actually from credit ratings which predate baseball leagues

when they said AAA i assumed it was satire