I’m sure they’ve crunched the numbers, but their could be a case for being okay with a potentially small decline in UK visitors to Orlando if it means they get large attendance from Europe in the UK.
These are fake numbers, but let’s say 500,000 UK visitors hit up Universal Orlando in a year, and then half of them decide to skip it for the UK park moving forward… but they get 8 million in attendance in a year at the UK park, they’ve grown their attendance globally, despite a small offset in Orlando.
I just can’t see Orlando getting that big a hit due to Potter inclusion in the UK, not when they have 3 major theme parks, a waterpark, and sunshine year round, with a ton of different experiences you will not get at the UK park.