FOX is the main network partner of the Big 10 and PAC. They must have followed ESPN and pulled some strings. Fox would to have USC showcased in their Big Noon Kickoff window.
When this happens, the Big Ten will include all three of the major TV markets. (They get New York and Philadelphia via Rutgers.) They also have DC and Baltimore via Maryland. Next, do they move south to try and get a couple of those markets?