if you look at your son from the side with his mouth fully closed, do you see his chin being overly stressed? if not, then no need to pull out the teeth.
Another concern is boys and girls are different. A fuller mouth is better for a boy when he grows to be a man. This is especially important when man are older(50+) and the muscles aroud the mouth become loose. A bit of inward is OK for Asian girls, but not good for boys (men) particularly when they are older(it will look like an old lady if you know what I mean). You have to look at your son's future development potential as well (look at you and your hu*****and). Borderline situation needs to be delt with carefully.
I would suggest you consult more orthodontists before making such a critical decision. I consulted 6 orthodontists before my son started his dental work.