@0:54 no its not a diffrent universe, they are always in the same sort of posts together. yes sometimes megatron is a gladiator who turns into a autobot after a few century's once his memories comeback. and yeah in some universes prime is chosen to be a leader as the last of the primes, but in 90% of the canon they were friends who were both low level workers who got into trouble. very rarely will you ever find a optimus who doesn't already know megatron. [before the war i mean, its why he calls him "old friend" alot when megatron dies for the good of evryone because he's acting like his old self.] like its usally small details like jobs or classes that are changed, and not how they met or how the story ends. usually with megatron being redeeming in some fashion like when he fought unicron in transformers armada. prime is one of the few universes that got ALOT of the older lore wrong in order to try and get a bunch of newer fans, like the other transformers shows on cn from the 2010's.
2:29 I just realized if you look at the transformer that gets whatever that gas thing idk what it is on him you can see that it is sentinel prime and you can tell that it is him from the clips of the race that happens in the movie