If I was universal, I would create a park full of niche things. I mean its easy to go for whats is easily popular but then its easy to mess up by not meeting people's expectation due to the popularity of it. However, focusing on IPs that only a small sect of people love, you have a lot more leeway and presenting the park in the old 1950s era Hollywood manner
I would break it down in Horror (Tales from the crypt, Universal Monsters, Hitchcock and other masters of horror, and I would keep it focused on old school horror none of this new stuff), Anime and Animation (Universal distributes a lot of really unique animated films with very disney like environments with super deep stories like Song of the Sea, The Secret of Kells, The Prophet, then all the Laika stuff. I would use those different IPs in the park. Also with Universal getting Nintendo, I would petition for Universal to get the biggest win that would make Lassetter and Co angry to another level and get Studio Ghibli theme park rights, also Universal owns a bunch of animes already so why not use them) A cult film area where they are represented, this is for all those films who everyone is ashamed to admit they liked ranging from the neverending story, labyrinth, live in park rocky horror,) Asian film area where you have godzilla, and chinese martial arts films represented, and lastly a true western area that puts frontierland to shame.