While on a much grander scale, this feels closer to Cartoon World than Animal Kingdom to me. Especially if Pokemon comes here honestly. I see the comparison but most of these aren't "real" so while yes a "fictional" animal kingdom, they aren't ALL animals or based on animals. They're bringing you into the world of these characters, not the world of these animals, if that makes sense? To me that right there is the main difference. The Animals are the star or part of the story here, but they are not THE story. The story at this park seems to be (while obviously immersing us in different 'Universes'), us interacting directly with these worlds.
Mario Kart has us starring in the race, HTTYD is us learning how to train our dragon, Fantastic Beasts seems to be about us muggles entering their world and finding beasts all around us, and Monsters is us getting a tour of Castle Frankenstein.
Maybe this boggles down to what Universal is compared to Disney, where I feel Disney is much more "Hey, look at this!" and Universal is much more "Okay guests, YOU are the center of this attraction" so to me EU and AK just seem like entirely different experiences. With or without Pokemon.