I think there are 2 ideas floating around.
1) Full merger with all 24 schools
2) New league with only 18 schools
To get to the right payout to keep everyone happy (~$50-60M tv rights only), it probably needs to be 18 schools.
From P12:
CU, UO, UW, UU, Stanford, Cal, UA, ASU
From ACC:
Clemson, FSU, Miami, UNC, NC State, UVA, VT, Pitt, GT, Duke (or ND as a Duke replacement if they agree to it)
Left out:
WSU, OSU, Wake, Syracuse, BC, Louisville and possibly Duke
I hate the concept of leaving these schools out but if it means creating a league where the above schools commit to this then it’s worth it.