Agree with the a better than 50/50 chance of acceptances at Babson, Lafayette, Trinity, Connecticut College. Maybe NYU because he’s full pay. If he applied early action to Michigan, he’ll get deferred and then accepted ONLY if he makes it clear that he will attend. They are very yield-conscious.
As for the rest, based on the info you provided, it’s tough to know. I don’t feel like I have a sense of your son from what you wrote. The ECs don’t pop. The only thing he has is grades and ACT, but nothing else to differentiate himself. Those LACs are casting a play (a class) and need to know the role he will play in the cast (class). This is especially true at Williams, Amherst, Bowdoin, and Tufts.
The wildcard in the equation is the boarding school he attends. If they have special insight and relationships with any of these schools, that could be in your son’s favor.
Good luck!