That's the best case scenario for me. If TZ has to go, then why not just do what Tokyo did and make an original story about a haunted mask or artifact possessing the tower. All they'd have to change is the music and the fifth dimension room, which could easily be done by filling that space with some new effects or an animatronic to go with the new storyline.
While Paris's new version still has the TZ branding, the new story focuses more on the little ghost girl being the main antagonist of the tower. The tower is so iconic at WDW, and it could still be called "Tower of Terror" without retheming it to Doctor Strange or some other IP.