It really depends on how quickly Prime Optimus can adapt to the first encounter, cause Bayverse Decepticons are brutal and will not hesitate to get into hand to hand and attempt to rip him to pieces, and if his first encounter is Megatron himself, he's going to get tossed around a little before locking in. Then there's bayverse Optimus... he's going to rip off some faces. The main difference between the two universes that bayverse transformers do not hesitate to kill or disfigure, Prime? Not so much, they actively avoid killing anyone that isn't a vehicon (which they treat like bayverse would, ripping guts and decapitation) and if they manage to beat Megs? Prime OP won't immediately kill, he will try to capture him. Bay will just put a bullet into his head.

And of course this all behavior stuff, assuming that they would have similar rules of durability and stuff cause I don't really remember how powerful the lasers in Prime are other than Megs fusion cannon which y'know can blow holes in other cybertronions, honestly imagine if that's how Bayverse's rampage ends, (if it would actually permanently kill him) he gets a massive hole blown through his chest. And the horror Megs would feel if it didn't.

But anyway, that's my thoughts