If they are looking at GotG for EPCOT I don't believe it will also pop up in DHS. Especially since the ride type is a simulator and pretty much any flying/fast driving movie could be slotted in. Oddly enough, that is actually difficult given Disney's catalogue. You aren't going to put a Pixar property there, so that rules out a lot. I suppose they could double down on John Carter, but since only 4 people saw the movie and it was a massive flop they probably don't want to be reminded of it. Same with Tron, though I think you could do an awesome CGI heavy simulator in that property. It just isn't popular enough as a movie. I would love to see them go old school with Rocketeer, but that could be because I loved that movie growing up. Sadly, the simulator concept doesn't lend itself to Rocketeer unless you got creative...he's more of a solo flying act.
I'm going to assume it needs to be a Disney IP though. I just don't see them going outside anymore even though that was originally more in line with the MGM Studios concept. Now that it is DHS, or whatever they should rename it to with SWL and TSL opening, I think it has to be a Disney property.