He's 400yr olds, no chance.
The thing with Maia, is by BJJ standards, he actually has good takedowns/wrestling. The problem is, the top end of the division is dominated by pure wrestlers and his wrestling isn't good enough to impose on them. The only thing he could've learned really, is striking to level the game a bit but he seems proper pillow-fisted - he never seems to hit hard, meaning it'd be a moot point anyway. He'd still be restricted to a 15-25min K1 match against guys who generally hit harder than him and are more explosive - he's got no athleticism really has he.
He's like a relic of a bygone era, albeit a very good one. Around UFC 50 He'd be a top-drawer contender or champion, but in 2017/18 you need more than he has in his locker.