I was a student from 2015-18 and there were only two games where students were turned away, Iowa 2015 (20 point comeback game) and Tennessee in 2018 for the Dilly Dilly shirts.Daughter stopped buying season tickets because the last two years she couldn’t get in to the games she wanted since they oversell student tickets.
From what I've heard, that hasn't happened that much since. I've been to quite a few games the last few years and there have been a good amount of open seats still in the student section for games, aside from Iowa, Kansas, and Texas for Tyrese Hunter's return. I'd say 95% of games in the last few years have been games where students were not turned away.