IMO, there should be at least two ACC teams in. The champ and the next best. If Miami wins out, regardless of if includes the ACCCG, they should be in. A 10-2 Miami team that flirted with the top 5, has two close losses on paper, and has quality win should be in. It's stupid that this is even a question
However, the elephant that no one is talking about, is the obvious bias towards SEC and B10 schools. The landscape has switched in recent years with efforts to make the B10 as the companion powerhouse to the SEC.
The 12 team playoff is just an underlying effort to shill this, force viewership and revenue towards those two conferences, and water down the rest of the P4. The B12 has become an afterthought and the ACC is quickly next, hence ONLY the projected champ gets in.