I don't know why kids do the overseas thing. They get paid but coaches aren't showcasing kids that are only there one year supplanting veterans on the team so these kids don't stand out that year. Look at Terrence Ferguson as the latest example, his stock didn't improve, he still looks like a late first round pick, maybe if he played college ball he could have had more exposure and could have improved his draft stock.
I think it depends on the kid. Ferguson had no choice he wasn't qualifying that's at least what everyone believes to be the case.
Bagley is so good he doesn't really need to be showcased. He missed essentially his entire soph season in HS after transferring and nobody cared, played his junior year and now if he transfers within California he'll sit until January, if he goes to Arizona he doesn't have to sit. But honestly he could not play at all his senior year and still be the best player in the class. A year in China isn't going to change that. As long as he doesn't get hurt, he's the first overall pick in his draft IMO.
I'm sure it's the dad. He's paid by Nike now, he figures I could send him to UK but that's just another elite kid at UK. UCLA isn't Nike and then he has to pretend to be a student for 8 months at either school. Or I can send him to China or wherever, get paid.
Sierra Canyon was sort of a disaster so I can't fault him for pulling him out of there. That team had too many egos and the coaches had issues too, one of which was Bagley's father.