My conjecture is that, yes, it's better to have a school with a large fan base in a game than not, but the game's national relevance is more of a factor than the schools playing.
Notre Dame and Cincy are both pulling for Baylor in a close game. With 2 losses (1 bad), they're not going to impact the top 4. An oSu win could move them into the CFP. As such. this game is nationally relevant and should move the needle closer to 4million.