Tfwiki doesn't say they are the same character and come to think, Megatron's brain have been critically damaged, maybe even destroyed which mean it's might be impossible to bring his consciousness back. For that, i think it will take something greater than the human's force to bring him back. So i think this new character, galvatron might be a seperate character from megatron and for an unknown reason they name him galvatron so it will "resemble" the dead Decepticons leader
Even though it is common that Galvatron is a Megatron upgraded, there are a few continuities there they are two completely separate characters (like Aligned and IDW). And as far as I know, there is nothing that says Movie Galvy is upgraded from Megatron.
there are only really two things we can be sure of at this juncture: 1) He might be Megatron 2) He might not be Megatron. I don't feel like I've been much help... ... Sorry
It could be Megatron reformatted. I mean typically the Spark is in the chest of a Transformer... and that's their core so... if that wasn't completely destroyed, they could re-animate him... no? Galvatron's been split from Megatron in some continuities though. Movie could be one of them, and we won't know for a few weeks... Schroedinger's 'Con?
I really feel that Galvatron is not Megatron but I have a feeling that Megatron will show up again "at some point" to reclaim what is his.
Overall body size, shape, altmode and face design suggest that he's either Megatron rebuilt, reformed or a new body based on him. I fully expect Megatron's 'spirit' to take over that body somewhere in the movie.
I don't think he is megatron,Megatron is dead .I think galvatron is either reverse engineered from the scrap of Decepticom bodies salvaged from Chicago or he is an ancient transformer who is repaired and revived by the KSI for their personal goals because in the trailer you can see that scientists are actually examining a transformer not building it, Well that is just a thought
Galvatron's body was probably created by humans based on Sentinel and Megatron parts recovered from the DOTM battle - explaining the inclusion of a Megatron head in a box probably for a scene in which they salvage his body. Megatron's head is probably used as a basis and essentially they create their own version of Megatron or Megatron's subconscious is transferred Galvatron Factory Battle set seems to confirm that he will gain sentience at some point
This is what I think. By that, I mean that I believe that Galvatron starts out fine and under control, but later, Megatron downloads his spark into the new body. In fact, I think it'll be cool if Sentinel and Megatron merge to become Galvatron, and what makes Galvatron crazy is the two minds battling for control of the body. That way, it can still be Megatro rebuilt, but seperate too.