I like the idea. That suggests that in the late '30s onward, Notre Dame would have multiple rivalry games in a season: back then, Navy was one such game; so was Penn (yes, the one that's now an Ivy League fixture). Throw in a Notre Dame / Boston College rivalry and that could get fascinating, especially in the Catholic community (said mostly tongue in cheek).
Seems like a heavy hitter in the form of Boston College could lead to a true eastern conference (BC; Syracuse; Rutgers; Temple; Pitt; Penn State; West Virginia; maybe Virginia Tech, Maryland, Cincinnati).
I wonder if the earlier appearance of an all sports Big East would cause the Metro Conference to get into football and be able to keep schools like GA Tech, Florida State and South Carolina onside?