This thread is a bit of a mix of feelings and (some correct, some incorrect) details - so getting to the key question, which I think @beebee3 answered:
That’s not a valid “basis” to break the ED agreement that your son signed with the college (and possibly with his HS). The only basis in ED agreements is financial. If you asked the college, they will tell you no.
But can he break the ED agreement anyway? Sure, in that is not a legally binding contract with any recourse towards you, and you can come up with a different reason, though this would need to be a conversation that involves your HS college counseling team, since they will get asked about it and it could reflect poorly on them in the future. It’s not great but that doesn’t mean people don’t do it. You can manage your own decisions.
As others have said, you definitely don’t want to break an ED agreement over the possibility that you may get recruited by an athletic team - you would want certainty of admission - and it is unusual in virtually all sports (but not unheard of) that this conversation would still be going on now. (Maybe the school didn’t fill all its slots like it planned, etc.)