I don't think the solution is a division or pod system, but simply a "rivalry" system. I think the two most important issues that need to be addressed when making the schedule is 1) each team needs to play a home/home series with every other team within a 4 year period. 2) rivalries. 3) schedule parity. 4) conference identity.
In a 16 team conference (or even in a 14 team conf.) each team can play every other school twice during a four year period with a 9 game schedule... But instead of divisions or Pods, each team would have 3 protected rivals. Then the two best records go to the conference title game.
If OU and KU or TX or whoever were to join, then NU would play OU, KU, and Iowa each year for example. Then rotate the rest of the 12 conference teams on a continual home/home series rotation no different than the B12 used to do, except the rotations for each specific team wouldn't be based on division, they would be based on Parity....
With 3 protected games, and 6 home/home rotating series, then each team will play their "un"-protected games twice every 4 years making everyone feel like they are a part of the same conference..... I have this schedule set up on a huge spread sheet for the entire B10 going forward like 20 years, I don't have time right now, but I can maybe link to the full schedule later this weekend. Looking at the entire body of the schedule addresses some of the parity issues and the "unfairness" of the "protected rivals" that you see listed here.
Protected games:
NU: OU, KU, Iowa
Iowa: NU, Minn, and Wisc
Wisc: Iowa, Minn, and NW
Minn: Iowa, Wisc, Mich
NW: Wisc, ILL, MD
ILL: OSU, NW, Purdu
Pur: OU, ILL, IU
IU: MSU, Pur, KU
MSU: Mich, IU, RU
OSU: Mich, PSU, ILL
Mich: OSU, MSU, Minn
Penn State: OSU, MD, and RU
MD: RU, PSU, NW
RU: PSU, MD, MSU
OU: NU, KU, Purdue
KU: OU, NU, and IU