If ESPN and the ACC were to expand the pool of schools deemed to qualify as meeting P-5 compatible opponents then 8+2 stands a bigger chance of passing. The SEC considers BYU games to count toward their P-5 requirement. The ACC does not not.
If BYU, the service academies and a couple of other schools were to count, as well as possibly reaching a compromise on the +2 requirement (lowering it to +1.5 or +1-2/3) then most would be happy. ESPN would lose out on 3-4 games per year so they may not agree. It's easy to say "just go 8+2", but the number of available P-5 games is just too small.