I remember seeing data that the only 4 cities that got significant graduates from all B10 schools were NY, Washington, LA, and San Francisco. (The Rutgers and Maryland pipeline to Chicago being nonexistent, so preventing the Windy City from being #5).
That plus the Stanford-Notre Dame connection, the $1.2 billion in annual research, and the $38 billion endowment probably make Stanford very attractive to the B10. They’d be the only conference that would take the last two into account, but I’m pretty sure it would make their slides during media day if it came to it.
Cal I’d have a harder time making the case for from the B10’s perspective beyond simple symmetry with two LA schools and two Bay Area schools.