I think the question is what HP-related land could they build in the UK which doesn’t replicate what they have in Orlando, for fear of reducing demand for visiting those parks. Not that I think Universal will do it, but they could build a proper Hogwarts. What we have in IoA is an external facade hiding a show building, plus an elaborate queue which wanders through internal and external scenes within the school. I think that there’s an opportunity to genuinely explore Hogwarts School in USGB by making a land which is just the school itself, not Hogmeads. The land would be mostly indoors, set actually in the school (so it would be under cover for all the right reasons) but can have outdoor parts where you explore the school grounds. There’d be endless opportunity to explore the classrooms, corridors, moving staircases, the House common rooms, eat in the Great Hall, the tent pole attraction could based around the Chamber of Secrets, magic shows in the Potions Classroom on the scale of the Ollivanders show, Argus Filtch’s emporium of confiscated magical oddities, a C-ticket ride through Prof Sprout’s greenhouses, etc, etc. It would be unique within Universal’s theme parks as the only place where you genuinely step inside the principal location which features in all the HP books. And for those people who love it, there’s more like this to explore in Orlando so if you want to spend time in Hogmeads, Diagonal Alley, take your first ride on the Hogwarts Express, accompany Hagrid on a wild ride through the Forbidden Forest,then all you need to do is save your galleons and apparate across the Atlantic…
As I said, it won’t happen as I think the WB rights issue is the serious stumbling block, but if they could get the rights I think there’s still plenty of creative space in the Wizarding World franchise to create something which would attract fans from across the globe and not cannibalise attendance in their other parks with Wizarding World lands.