On the field, Mack hasn't done anything that can't be done as well or better by Wright and Kmet. The real impact (if he becomes ineligible due to academics) is the effect it may have on recruiting. This would only add fuel to the fire of the negative recruiting that already takes place.
We all know what our competitors are saying "You don't want to go to Notre Dame. The academic demands are too hard. You will never be able to stay eligible. Look at what happened to ___________ and ____________ and ____________.... Notre Dame wants you to attend classes and do your own work. Come to our school instead. We can set you up with some easy classes. In fact, if you come to our school, you won't even have to attend classes."