So what Lands and Rides and shows would you like to see at a second park?
1. A Main Street similar to IOA's, not necessarily in design/aesthetic but in purpose, setting the tone that you're going to experience something different to USH proper.
2. A DreamWorks land. I'm not the biggest fan of DW's output, but I think properties like How to Train Your Dragon and Kung Fu Panda could provide for a good family-friendly land. I'd make KFP either a dark ride or a boat ride, while HTTYD should be a family coaster. Could include meet-and-greets for DW characters, or even a small show for fairy tales retold through a Shrek lens.
3. Wizarding World expansion. Obviously this is one that's been talked about enough, but it's really unavoidable. I love Diagon Alley in Orlando, but if USH wants to stand out, a new land in SoCal shouldn't be a port at this point. Recreate London, sure, but go all-in on a Ministry of Magic ride/experience. And I know Fantastic Beasts is kind of a lukewarm part of the Wizarding World now, but I think a supplemental ride focused on the idea of encountering beasts could be good (rather than focusing on all the Grindelwald-related/time period stuff). Make it similar to the idea of Hagrid's coaster but base it on the idea that, say, we're visiting a beast sanctuary Newt founded, only the beasts get out and we have to "help" find and wrangle them.
4. A Nintendo expansion. I'm not a big Nintendo fan, either, but I'm hoping for the best with USH's land. I was more excited for the Donkey Kong coaster than I am Mario Kart, but since that coaster apparently isn't happening at USH, then a second land would be great for it, and whatever other Nintendo properties people typically lean towards, like Pokemon or Zelda.
5. A Classic Monsters land. I'd model this as a "dark version of Wizarding World," with Hogwarts replaced by Dracula's castle looking over the land and the streets of Hogsmeade replaced by a Transylvanian village. I'd have the primary ride be based around the idea that Dracula's castle is seemingly abandoned, allowing for tourists to visit, but, of course, that's not true, and our presence unleashes evil. The ride could travel through the castle, catacombs, the windmill from Frankenstein, whatever you want, encountering Dracula, the Wolf Man, and Frankenstein's monster. I'd also close The Mummy over at USH (and replace it with a new thrill ride, of course) and build a better Mummy coaster in this land instead based on the idea that the influx of tourists to Transylvania has drawn opportunists, one of whom has acquired the sarcophagus of Imhotep and brought it all the way here to show it off (only for Imhotep to awaken). Throw in a walkthrough experience/show and - if I'm dreaming big - a Black Lagoon water ride.
6. Middle-Earth. I know this is a longshot, but considering it's been rumored off and on for years and the fact that I love Lord of the Rings, I'd love to see a land based around it. Not sure how a ride could fit "in canon" with it, but honestly a part of me would just be so excited to step into this world in some way, whether it's the Shire or Gondor or wherever.
7. New York City. Not the most obvious choice, and it doesn't even have to be NY, but a city setting could allow for properties to be put together in one land that can't hold up a land of their own, like Fast and Furious, which Universal has done dirty in Orlando but could make for one hell of a rollercoaster, or a property that could adopt a similar shooting gallery system to the one that Men in Black has to mix things up.
It's easy to say I want to see attractions based on old rides - I want E.T. back! I want Back to the Future back! I want Jaws back! - but I know that's just never going to happen. All I know is that in a second park, I want more actual rides, particularly themed coasters and water rides, simply because we have such a shortage of them at USH.