Updated potential land IP's in order from most to least-likely IMO.
- DreamWorks (Shrek, How to Train Your Dragon, Kung Fu Panda, Madagascar, Trolls, etc)
- Lord of the Rings/ The Hobbit
- Super Nintendo World (includes Mario, Donkey Kong, Bowser, Yoshi. Could potentially include Luigi's Mansion and other Mushroom-Kingdom-related IP's)
- Fantastic Beasts (Harry Potter spinoff)
- Pokemon (Nintendo IP)
- The Legend of Zelda: Hyrule (Nintendo IP)
- Star Trek (currently unused at any Universal park that I know of)
- Classic Universal (Jaws, Back to the Future, Ghostbusters, etc)
- Universal Monsters (Dracula, Mummy, Frankenstein, etc)
- Metroid (Nintendo IP)
- Splatoon (Nintendo IP)
- Godzilla (currently unused at any Universal park that I know of)
- Ready Player One ('cause Spielburg and 80's)
- Hello Kitty (kill me now)
- Illumination (unlikely, but possible)
- Stranger Things (Netflix IP)
- Jurassic World (unlikely, but possible)
- DC Comics (very unlikely, but possible. Don't kill me)
I would say this as the most likely given circumstances:
- Super Nintendo World: The Mushroom Kingdom (Mariokart, Donkey Kong Country, Yoshi)
- Lord of The Rings (Universal's theme park relationship with WB and the allowing of the Amazon show comes to play)
- Fantastic Beasts (Paris or a new cityscape not yet seen in the film series)
- Dreamworks Animation (Shrek, Panda, Trolls, Dragons, all in a NFL-esque land)
- Original Concept (the park can't be entirely IP's)
- Sanrio (Hello Kitty, Chococat, Kero Kero, and other characters)
Things I don't see:
- Super Nintendo World: Hyrule (Saving it for one of the other parks at UOR)
- Jurassic World (Islands)
- Illumination (Seems to already have the presence set at USF, regardless of the quality as of now)
- Stranger Things (Halloween Horror Nights will have that IP covered for a long while presumably)
- Ready Player One (Not a franchise, doesn't even have a sequel published, and may not be able to hold itself up as a reliable IP regardless of the fanservice)
- DC Comics (While not impossible, is more improbable due to presumably legalities that would have to be faced between Universal, Time Warner/Warner Bros, DC, and Six Flags)
- Godzilla (Can't hold on it's own, and Kong already fills that hole in nicely)
- Anything Classic Universal (While it could be profitable, it is more of a risk because it could get dated fast)
- Classic Monsters (Blame the Dark Universe)
And throwing this one into the don't, Armada as while that's being made to film, it's not fully in production yet nor should be a guarantee to see in theaters just yet.