As it stands there is a thought that Guardians would be more suited here than at Epcot. Which may be true for the park, but not the location.
Yes it's a movie attraction. Yes it's futuristic. But DHS needs all the help it can get, and GMR should be the all encompassing marquee attraction for the park. Which is why it needs to stay as an updated and refreshed GMR. Mickey is a perfect fit for the Art Deco of Sunset, on the Ranch expansion plot. GMR again needs to be the parks anchor. And Guardians could easily fit into a phase 3 elsewhere in DHS in a purpose built building to fit it's environment. It's not an Epcot IP.
But that's the most expensive option. Even if it might be the best.