Due to the need for a big draw, I think the only mistake would be putting Pokémon and SNW in EU.
I still say the whole right side of the park (Kidzone to MIB) should be themed to Japan. I forgot who originally mentioned it, but Pokémon, Fast and Furious Tokyo Drift, Godzilla all behind beautiful Japanese theming would be great. Hello Kitty isn’t my thing, but it would would help to have another dark ride with colorful characters on that side of the park.
I think Japan was an option but Pokemon is already too big and would take up too much space to justify any of the other IPs at this time. Also truthfully, the parks should not touch the F&F ip for the next five years. Additionally we have to think about HHN and if Pokemon Company is okay with Universal putting up houses in their area of the park...(likely answer is going to be no)
With ET likely staying and not going away, it already takes away from the footprint that is possible for that area as well. So the space gets I'm also assuming they want a large space where they could host potential Pokemon Go events that are isolated in a single area which means its going to require significant open space outside of queues and show buildings. I think people forget how problematic Pokemon GO is sometimes in creating congestion/people going to places they aren't supposed to go to. Only way for that to happen is with the new park.
Other point is expansion area, if Pokemon overperforms, logistically, we could end up seeing day one Hagrid's Motorbike level queues for three weeks. Those queues take a lot of walkway space. At least with the EU hub is massive enough where things like that wouldn't be an issue.