It’s up to BTS on whether they want to go or not. They went to knowing bros, you quiz and Taehyung went to his friend’s show bcos they wanted to. RM used to be regular on a kshow too. Jungkook attended one that was based on Vlive. It’s pretty transparent that they are too busy for that plus they have their own ones catered to them like run bts, BY, ITS etc.
Plus I don’t see how this is relevant to having Korean choreographers? They work with choreographers that suit them, what’s talent got to do with nationality?