Thank you. I've talked about this subject before. There's really nothing gained by redshirt anymore. Redshirt is for 5 year guys and development. Yes, you can cite a couple examples like Henry, Skalski, but they're few and far between.
2 things happen. As you stated, they graduate. You may have a guy for 4 years but rare. If they're not good enough yet to get PT after 3 years, they'll transfer. Actually a good discussion to be had on this subject.