This thing is fun to play with, and is to be taken with a major grain of salt since we've never had ND in the playoff mix and thus no historical data, BUT...
https://projects.fivethirtyeight.com/2018-college-football-predictions/
According to Silver's projection tool, if all the favorites win this weekend, the team of Alabama/Clemson/ND/Oklahoma/OSU most likely to be left out is.....Notre Dame. OSU's chances to make the playoff are 69%, followed by OK at 68%, followed by ND at 62%. Is it really a foregone conclusion that ND gets in with what has turned out to be a very vanilla schedule and no championship game?