There's a lot of great feedback already.
As a Notre Dame grad, I can attest that the school is a pretty special place. The average admit ACT score last year was over 34. ND has become a highly selective place.
Notre Dame's 2017 baseball recruiting is done. But they do have a club baseball program with some very talented kids.
I echo the feedback on late applications and on academic D3's. There are still spots for very special kids and as noted, his academics are an incredible hook. Money is available at many places, both merit and aid.
Immediately cast a wider net. He should engage the admissions reps and the baseball staffs at schools where your son would be a fit. Today.