This is not true,
Themed attraction licensing is partly owned by Warner Brothers along with J.K. Rowling, and Universal Destinations & Experiences and would transfer to Netflix as nothing more than the “licensor of record,” similar to how Disney’s purchase of Marvel worked.
Netflix now steps into Warner Bros.’ role as the studio-side licensor, but Universal’s Harry Potter operating agreement remains fully intact and legally protected. Nothing changes operationally. Anything announced must be fulfilled, the only thing that may change is
future development. I don't see any reason why Netflix wouldn't want to keep it rolling.
Keep in mind that J.K. Rowling still owns all the Harry Potter intellectual property and retains all creative decisions regarding the series/moves/theme park content. Netflix couldn’t do anything with Harry Potter even if they wanted to.
The only things Discovery/WB are keeping are cable TV networks, news operations, live sports, and international TV networks. Everything else is being sold as of current reports.
Nothing is set in stone since regulatory approval is still required.