If its through decision again, its going to be Floyd.
Most likely because this fight will be played at Mayweather's territory and though he didn't own the fans but he own the judges.
One thing I also noticed, every time there's a rematch for Manny, he always win the 2nd time, so this one big factor is also an advantage of Manny.
Manny have that capability to win back after his defeats but it can only happen if chances to have this rematch and play according to his type of fight and not to allow Mayweather to dictates the tempo of this game, but if same thing will happen like from the last fight it will make it boring and much better not to have the rematch.
It's because Manny adapts that's why most of his rematch after a lost turns out to be a lopsided victory for him. However, Floyd is a different fighter, him and Floyd are just above the rest, that's why they are elite fighter.
But even if Manny lost again in the rematch, at least it will be a good match as compare to the first one wherein his shoulder are hurt that affected his performance.