If a Pac 12 team (i.e., WA remains unbeaten) has a legitimate claim, I think they get in if for no other reason to pull in the West Coast and because they haven't been represented in the CFP recently.
An undefeated FSU will have to be included - they've been in the top 4 for a while and I can't see a 1-loss team jumping them if they remain undefeated.
Winner of OSU-MI will surely wax the B10 West in their championship game so the winner of that game is definitely in.
That leaves Bama-Georgia. If the Dogs win, they're automatically in. If Bama wins by 2+ TDs, I think they'll automatically get in. If it's a very close game that Bama pulls out late - who knows? Would TX jump both if they're 12-1? Would a close loss to Oregon in the Pac12 championship game disqualify both Oregon and Washington? If Oregon beats UDub by 3+ TDs, would they jump into the mix?
Some team who is really good and has a reasonable argument to be included is going to be left out - maybe more than 1 team. Too bad we don't have a 6-team (which I've always thought was the ideal number) playoff this year. Other years, there weren't 6 teams who legitimately could have any claim. But, this year, there are definitely that many.