Yeah, that's the data that matters.
n is still pretty small for neutral site postseason football games. I think you have to throw out the 1v16, 2v15, and maybe 3v14 and 4v13 in basketball because that gap is way bigger than anything that would have been in the CFP.
5 beats 12 35% of the time; 6 v 11 38%, 7 v 10 40%, 8 v 9 50%
https://www.nbcphiladelphia.com/new...adness-first-round-upsets-by-matchup/3806901/
Last 5 years of CFP it looks like the lower seeds were 4-6 in the semis.
Admittedly, this is still very apples to oranges, but a first level glance is consistent with upset rates not being wildly different between the two.