He would count towards a class, but I believe if he enrolls in the summer they could count him (or whomever) towards next year.
My guess is that they continuing recruiting the HS kids they really want and if they all come and fill up the spots available for this year then we evaluate how we look in Spring and then pick up some of these kids in Summer. It's too late for them to enroll for Spring anyway and there are likely to be more players available after Spring practices anyway so why not:
1) Keep spots for this year available fro kids that will be with you for several years (HS kids)
2) Evaluate what you have (maybe kids step up with another year, better coaching, different system) or maybe (knock on wood) someone gets hurt and we need depth at that position
3) See whom else becomes available.
We need to be careful though with who we are taking, we can't just waste spots on the Tommy Kennedys of the world since we are currently more impacted by the yearly cap than the overall roster cap and it hurts even more when you trade one of those spots for a 1 year rental.