If your son's grades continue on the path they have always taken, you're probably fine. Just make sure they do. Remember that they may ask for mid-semester grades before the decision in December, and for sure they will want fall grades after admission, and then a final transcript after graduation. At HAs, the grades cannot drop too much senior year, even with a slot, even in the spring. There's a reason that I started another thread called "no senioritis".