247 shows Hubert as in the 2016 class but he took a mission so his clock wouldn’t have started until 2018. 2022 would be 5th year with 2 redshirt years so he should have 2023 with the possibility of a medical redshirt in 2024 if he wanted to pursue that.
I really don’t know the criteria they use and if it has gotten tougher to get the waiver since they changed the redshirt rules to 4 games. I believe that you have to wait until your eligibility expires before you can apply so it’s a long way off for Hubert. If he has an all-conference year in 23, I’d imagine he would put his name in the draft instead of burning another year of his prime.