I think the question is, why would a player "Not" follow their regiment. Rosters are bigger this year. Everyone's fighting for playing time. If you're not grinding, you risk getting splinters in your rear or possibly cut. My son's on scholarship for a D1 in California. He's going into his 2nd season this year. When Covid shut them down, we setup a gym at the house, and he went back to his little league coach that had a cage in his backyard. This was his plan, we just help him and supported him. After all the waiting he finally got back to weights, practicing, cages, etc. at school. He saw many guys struggling, and they were the ones that didn't do anything over the remainder of last season and summer.
As you said, my son, too, will be done at Thanksgiving, and will report back in January. His coaches have given him a schedule to follow over the break.
Come January, they'll know who followed it and who didn't.