Just my opinion for what it is worth.
Your son should go where his coach has secured a spot for him, coaches have reasons why they place players where they do, because they have relationships, because they haven't had complaints, and based upon the players ability.
I am not sure of your statement that he goes to school in North Carolina and wants to get back to Texas for college ball? Did you mean just for the summer?
If your son has signed a contract, he cannot go play somewhere else without a release.