the right circumstances.
2 losses for a potential 4th place team, with an upset in a championship game, or a 1-2 loss Big 12 team, and a 12-0 BYU with the tough, Independent schedules we are seeing, would be very likely to get BYU in.
Take 2007 for example. In the final regular season poll, #2, 3, 4, 5, 6, and 7 all had 2 losses. #4 Georgia was 10-2, and did not play in the SEC Championship game. 12-0 BYU gets in over them in that scenario.
The correct answer to the question, "Would a 12-0 BYU get into the playoff," is, it depends. But, when you look at certain seasons where there was a 2 loss team is in the top 4, I'd say it's extremely likely that a 12-0 BYU gets in under that scenario. In other years, there have been 1 loss teams that did not win their championship. That would also leave a window open for BYU, if they were undefeated.
In the last 10 seasons, there has been at least 1 2-loss team in the top 4 of the final regular season AP poll (I'm going off of that, because it's as good as any measurement, and the playoff committee has its own, distinctive criteria that I won't try to replicate) 3 times.
2005: #4 Ohio State-2 losses.
2006: #4 LSU-2 losses.
2007: #2 LSU-2 losses, #3 Oklahoma-2 losses, #4 Georgia-2 losses (also, among others, #5 Virginia Tech-2 losses).
Going back to 1990, there are a few more seasons where there was a 2-loss team in the top 4 of the final regular season poll:
1990: #4 Miami-2 losses.
1999: #4 Wisconsin-2 losses.
2001: #3 Colorado-2 losses.
2003: #4 Michigan-2 losses.