Yeah I think the conference realignment is MOSTLY driven by football money but there are some other considerations. I think USC and UCLA were accepted because that was almost purely about carriage fees and Fox Sports wanted it to happen. Fox added Oregon, Washington, and California markets. Stanford didn't have a dance partner and they were irrelevant to Fox Sports. You could say Cal was a possible pairing but neither Stanford nor Cal matter to the networks in terms of viewers or fanbase. B1G had no football-related reason to add Stanford- I assume if they added Stanford/Cal then Fox Sports would have to increase the payouts proportionally- Ohio State isn't going to take less money to add more teams to the conference. Could the B1G have gone to bat for Stanford and Cal, and told Fox Sports- "We are adding two west coast teams without much of fanbase or market share, oh and also no incremental carriage fees- give us another 200 million per year for those teams"? Sure, but I don't think the squeeze was worth the juice at the time.
But if Stanford reached out to Notre Dame and somehow convinced them to pair up , then it's absolutely a no-brainer (I'm skeptical it's true, but if it is, then the point stands). Notre Dame is a top tier academic institution but it isn't mentioned in the same breath as the most elite academic schools like Harvard, Princeton, Yale, and Stanford. As you said, there are Olympic Sports too, so B1G would look at the overall picture and say, "Academics + olympic sports + Notre Dame make up for Stanford not being relevant in football." I think the B1G would definitely be willing to tell Fox Sports, "We are adding Stanford and Notre Dame now, fork over another 200 million" and Fox Sports would oblige. So IMO it's not that farfetched, and I don't think any previous rejection of Stanford by the B1G has any bearing on the decision now.