If Pitt pulls off this upset it helps clarify things and open a spot for someone.
With a Miami loss, I think that the ACCCG winner would still get into the CFP (even if Clemson lost to USCe, then beat Miami to finish 11-2) while the ACCCG loser would be a 2+loss non-Champion and obviously out.
That helps if you are ND, tOSU, USC, or WSU.