It's pretty hard to say at this point. The whole idea with GP being evil is very baseless and there's no indication that he would do such a thing. If he was planning to betray Zenno, why would he wait until now? Why wait until Goku propose the idea for this tournament? Who knows? Maybe the dude is actually pretty chill, but he couldn't help it that his smile is beyond creepy.
Regarding who's going to win: I predict a draw between U7, 11, and 6. The other universes might have a chance to survive. If their fighters are KO'ed and lie unconscious on the ring, it doesn't count as ring out. They are only incapacitated. We see Hit KO'ed Narirama, but he's still not ringed out yet. So if every universe, with insane luck, has at least 1 fighter on the arena when the time runs out, they get to live. We just have wait patiently and see how things go.
From the look of it, Jiren and Hit are going to fight. Somehow, Hit will be KO'ed, but still managed to stay on the ring, and Goku jumps in to fight Jiren. Freeze is probably going to have a fight with Toppo, while Vegeta gives Cabba an ass kicking for his back tingle crap. The others are going to be KO'ed or ringed out eventually. I'm pretty sure Toriyama is gonna have Piccolo fight with the Namekian(s) from U6.
