As you know…these schools are reaches for just about everyone who applies. Your son is a strong student. He can apply and see. As long as he understands that more than 90% of kids do not get accepted to Yale or Princeton…
He might get accepted and he might not.
In the meantime, I would strongly urge you to find two sure things for admission, and affordability that your son would be happy to attend. Find those now.
It’s easy to find those reach schools. It’s not so easy to find those sure things.