When kids transfer from one MIAA school to another in 8th grade or for 9th grade it is always for the purpose of repeating another grade. Kids are doing that in the NE boarding schools too. There's a sad scurge of parents who shuttle their kids around prep schools for this reason. Can't repeat a grade at the same prep unless you can show academic cause for needing to. Read: flunk a grade. So you shuttle around to a different prep to position the young recruiting game. Calvert Hall and Boys' Latin both do this with a lot of gusto. Happens at the Exeters and Choates too.