It is the reason the Big Ten (and other FBS conferences) didn't support the ACC's proposal back in 2014 to eliminate the division requirement and let each conference decide how it picks the 2 teams to play in its conference championship game.

https://www.bcinterruption.com/acc-expansion-syracuse-pittsburgh-louisville-notre-dame/2014/2/4/5379230/acc-votes-to-send-title-game-legislation

The Big Ten believed (right or wrong) that the ACC would allow Notre Dame to play in its conference championship without requiring the Irish to join the conference in football and play a full conference schedule.

I spelled out the exact bylaws I am referring to in another post (see hyperlink). The reason the Big XII can play a conference championship game in football because it qualifies under Option 2. The reason the Big Ten supported adding Option 2 because Option 2 ensures that Notre Dame can't play in the ACC Championship Game while remaining an Independent. Option 2 isn't an option for the ACC anyways because you can't play 13 conference games during the regular season, which would be required by the ACC if it eliminates the divisions, unless 1 of the members is located in either Alaska, Hawai'i, or Puerto Rico. per another NCAA bylaw (if you want me to really cite that one too). Basically the only way a DI school can play 13 regular season games in football is if 1 of the games is @Hawai'i.