I looked into this a few months ago, and I'll try to post the link I'm referencing after I find it. iirc, this season the NCAA will allow more than 85 scholarships to accommodate for the one free year of eligibility. However, by the 2022 season all teams need to be back within the 85 scholly limit. So teams that haven't suffered any attrition, could be looking at 105 scholarship players this season. You are still only allowed to sign a maximum of 25 new scholarship players per season, so in some instances, teams may have below 85 even after signing 25 newcomers. I'm not sure of how this is navigated, but it's my impression that walk-ons receive scholarships for a year or so.
https://www.ncsasports.org/football/scholarships
"With eligibility being expanded for 2020–21 and college programs being able to go above their scholarship cap, Division 1 FBS football programs are likely to take on a full 2021 class and be close to 105 scholarship athletes in the fall of 2021. For 2022, many programs will have to get back down to the 85-player limit."