Unlikely, and he'd be a bit crazy to stay. If he has the skill Reilly says he has, he could start in a lot of places. No reason to spend his career on the bench at Nebraska.
It would depend if/when he left though, right? Tanner has 2 years, so 2019 would be either POB (RsJr.) or Gebbia (RsSo). If POB were to transfer after the during/after the fall season, I think he's sitting until 2019 anyway.
I'm a big believer in Gebbia; I would imagine that if POB can't beat out Lee, he won't beat out Tristan.
I think you must be smokin the chronic
Gebbia is a better overall prospect. POB has a better knowledge of the playbook and more size, but Gebbia can acquire those with time, and he has the better arm of the two.