This happened this year at son's school in football.
Kid lost the starting QB competition and transferred to the HS in the next town over. Parents got a condo address and said the kid and dad moved. Within a couple of weeks he was the starting QB at new school.
Teams faced each other in the playoffs and I noticed our guys were hitting him harder whenever they got an opportunity.
I don't know the inside relationship between the new school and the family but it did happen that fast.