"Logic" says that Rochell would redshirt. BUT Coach doesn't pay any attention to that. Coach constantly boggles my mind by viewing every player as just who they are in relation to the team winning the next game. Sure, he has the future in his mind, but it appears NOT to come into play unless his choice of players is essentially equal.
Therefore, Isaac might NOT redshirt. If Coach and Bobby-the-D, are looking for the second DE [other than EV] to back up Sheldon and Stephon, and they think that Isaac is a better contributor towards a win than Jarron or Chase [not an impossible situation], then Coach will say "lace 'em up. big fellow."
I'm just going to sit back and enjoy the ride on this one.
By the way, it is my humble opinion that Bobby-the-D needs a little more depth-system development in his systems, so he can't be predicted by a "satanic master" or even a USN schemer [who saved unexpected variations for us all season]. Diaco is a great "structural planner" and teacher of subtleties of technique and gap fitting. He is NOT a master-of-disguise or a confusing shifter of personnel placement and function. Admittedly he has also been hamstrung by the fear of rookie DBs getting homerunned, but this year that should somewhat go away. To get better as a Creator-of-Confusion, Diaco needs as much veteran understanding as he can get on the field. This could mitigate against too many of the rookies seeing a lot of action. Although, in Isaac's case, DE would be less demanding on the "confusion" angle.
I believe that Diaco is VERY anxious to install such unpredictability. In his very first year, he tried [just as a one play experiment in a couple of games], the "stand up disorganized milling around" thing that you see some NFL teams throw in there occasionally --- so no one can really get much of a pre-snap read. He used it a couple of times last year too. This gimmick is not actually disorganized but crazy-like-the-fox and demands good acting and veteran predict-the-snap savvy. It's just a symbol to me that Bobby-the-D IS willing to take some risks and grow beyond being the creator of a robotic machine type of defense.