Yeah, as much as I want Animal Crossing, it also has its own obstacles. AC is best suited for a family friendly area that is assessable to younger children, but as
@moth mentioned, that niche is already filled at each park. USF has DreamWorks, IOA has Suess Landing, and Epic has HTTYD.
The other concern I have is that allegedly Hello Kitty/Sanrio has underperformed in Orlando compared to the other Universal Parks. Sanrio has a very similar audience and a lot of overlap with the Animal Crossing fanbase, which makes me concerned that AC also wouldn't be able to perform well at UOR.