The idea of a Harry Potter reunion without JKR involved is a total Impossibility anyway, she made sure of that with the Wizarding World licensing agreement (which back in the day everyone hailed as a badass defense of poor indie creators)https://twitter.com/mistertodd/status/1309017397270130691 …
I actually consider it somewhat unlikely she'd put any of her kids in charge of her IP after she dies (a lot of people don't, but JKR especially seems like not the type)