Way more than that. Each class is going to be larger to account for portal attrition. And remember, the total roster size is decreasing, but the number of scholarships is increasing. There will be whole lot more opportunities to get a scholarship to an FBS school.
The walk-ons are affected, yes, but a lot of them will have G5-level scholarship opportunities that they wouldn't have had before. And the ones who prove themselves at G5 level will have upward portal opportunities, akin to the way the best walk-ons used to be given scholarships (albeit at a new school instead of their current one).