I guess it would depend on the comment you made above:
"He attended two previous camps there, the last at which both the hitting and the head coaches told him he would be hearing from them."
So did he hear back from the head coach or recruiting coordinator within a week or so from the prior camp? While he is not yet a Junior and there are restrictions on contact, as you noted, the school already has 9 commitments from his class. So they have clearly found a way to connect with those players. If your son has a travel coach who talked to the head coach or RC, then the interest is genuine. If not, they may be stringing him along.
My recommendation would be to keep the school in consideration but see if your son can play in front of them another way, perhaps at a PG showcase or tournament event through his travel team. Going into his junior year, he needs to cast a wide net if he hopes to play D1 and be seen by as many schools as possible. $$ and time spent on just one school's camp may limit those chances. But if he plays well at a showcase or tourney, his dream school may step up the interest (particularly if there is buzz around his play).
Good luck!