I've actually got four IP predictions for the park all based on the fact it's stuff Uni already has the rights to. I only expect at the very least one of these to appear. I would be shocked if none of them do.
The first two I think are the most likely.
1. This one is obvious:
Jurassic World. This is arguably the biggest IP Uni has at their disposal that isn't licensed from another studio. It can definitely have space over two parks. Now, I know a Uni monorail is totally not going to happen (it's not very likely, at least), but can you imagine if they had one that went into the park like at Disneyland and went through the Jurassic World gate as it entered? Ah, I can dream
2.
Fantastic Beasts and Where to Find Them.
The more I think about it the more I want a Potter phase 3 to be as different and new as possible from Hogsmeade and Diagon Alley and focusing on a new story that's not about Harry and the gang is perfect imo
These next two completely depend on what happens with Nintendo at USF.
3.
Pokemon.
This is the biggest franchise they have outside of Mario. If it doesn't appear in USF I expect something to appear in the new park.
4.
The Legend of Zelda.
Another big franchise from Nintendo that if it doesn't appear in USF could very well happen here. I'll also say how much I would love to walk through Hyrule Castle Town recreated like Hogsmeade
Reminder, my list is completely based on things Uni already has theme park rights to.