You have to factor into that fight that Maia wasn't training his ground game/grappling at the time. He was training almost exclusively striking. This Maia has gone back to what brought him to the game and shows a marked in improvement. Fitch's sub defense IMO is overrated-he was in bad positions with Eric, Diego almost got him with a guillotine in there fight.
Edit: I really need to see Penn/Fitch see if John was in any bad spots in that fight.
BJ took him down and got his back, not an easy position to escape from but it should be interesting to see how a guy like Maia whose a lot bigger than BJ does if he can get it.