Had a conversation today about high school football. Lots of contingency plans being discussed/made if the season can't start on time or if it is interrupted.
I'm sure the NCAA and various conferences are having the same kinda of discussions. They want to play. We all want to play. What happens if we can't?
If you were coming back for your senior or redshirt junior year and there is substantial concern that there won't be a season there are some real motivations to come out. If a school is closed the kids can't train correctly and they don't have access to facilities. Without campus dining many of them won't be able to eat correctly/maintain weight. For linemen that's a big issue. If they come out they get their contract and then aren't staking everything on a season that might not happen.
Think of it this way, if you were a baseball player who was drafted last year as a junior, knowing what you know now would you have come out then or gone back for your senior year? There will be many kids who chose to go back, never had a senior year, and will see their stock drop in this year's draft. Sure, the NCAA gave spring athletes an extra year of eligibility. That's good for kids who aren't going pro. If you are going pro it just makes you a year older.
If Trevor Lawrence decided to come out in the supplemental draft there would surely be a feeding frenzy to acquire him and he would be paid now what he would be paid next year as a first round choice.