My issue is aesthetics.
If this hypothetical coaster is in MK, it will be an eyesore that could tower above Cindy's Castle.
Everest is the highest point in the world and at Disney World, so putting this coaster in AK is not possible.
EPCOT could use more rides, but dislocating the visual of the Spaceship Earth seems wrong too, but not impossible.
Therefore, I could see Hollywood Studios having a mega coaster. After all, HS needs something, ANYTHING, to keep people engaged for the day. Were it not for Toy Story, Beauty & Beast, and Fantasmic, my family could just as well skip HS. This is our least favored Park and it will be years before anything new is added.