FWIW, Waterworld is actually rumored to be in the running for one of the expansion pads at Epic Universe. Though this could be a placeholder until another more popular IP comes along.I know my opinion is unpopular, but I really want Waterworld for this area - at least for the Sindbad end of the land.
It could be a good idea to expand Seuss Landing into some of the space to create Mt. Crumpit. If they created a permanent seasonal location for How the Grinch Stole Christmas, it opens up a ton of possibilities for repurposing the BMG Soundstage.