If five guys leave, osu isn't making the numbers tighter, they are making the number larger. To jettison one more player would not be more difficult, osu doesn't seem to mind floatsam.
Also the new kicker technically, isn't a grey shirt either. He's a walk on. If you pay your own way you are a walk on and only a walk on. It's been thrown around on here and other sites that he is a grey shirt. He isn't a grey shirt. But no one knows what to call a walk on to scholarship player. I've got an idea, let's call him what he is, a walk on to scholarship player. WOTSP (REGISTER, COPYRIGHT, AND PATENT APPLIED 2/3/17) He has himself said, he can and will play if needed for the '17 season, that is not a grey shirt. I take that to mean one of two things, if he beats out the current kicker, or if the current kicker gets injured during the pre-season or in the regular season. NB has a little injury history, and Myer doesn't seem too enamored with him either, so it's not in another realm that the freshman plays this season. NB could also get the boot, no pun intended.
If five players or more go bye bye, HB could potentially be put on scholarship. Even if that doesn't happen, by paying his own way the first semester, he doesn't count against the roster limit, he is a walkon and he is eligible for the '17 season, by norms, that excludes him from being a greyshirt. The other part of being a grey shirt is when one's ncaa five year clock starts ticking. A grey shirt is usually done to separate years with players of the same position. If HB doesn't play during the '17 season, his five year window starts in '18, then technically he would be a grey shirt this year. It is extremely rare for one to pay their own way the first semester, to be a grey shirt candidate for the following year. It's the first that I know of at osu. It's also rare for a grey shirt to be 'eligible' for the season in which he is trying to be grey shirted. Usually, in the case of osu, they would 'sit out' the fall semester, Aug.- Dec., then enroll the spring semester, Jan. - Apr. and count towards the following year's scholarship total.
Here's the TLDR; if the frosh plays in '17 he isn't a grey shirt. If he doesn't play during '17, even while being eligible to play by paying his own way, he is a grey shirt. Of course that's today. If the ncaa does allow fresh. to play four games and still be redshirted, he could still have four years eligibility to follow, even if he played four games, depending on what part of the season the four games are allowed to be played. I suppose in that case he could be considered the first redshirted-greyshirt in osu history. That I know of.