General Recruiting Statement:
If a player does not qualify, the letter he signed is no longer valid so he can be recruited again. So, hypothetically speaking, let's say there's a stud juco player who signed and then a class didn't make it through the clearinghouse. He would have to retake this class and he would technically be a recruitable athlete again. Good luck getting a school to admit all of this on the record so all of the other schools would know.