The reasons for holding off could be one of many. These are just off the top of my head why they would be held back a day:
1) There's a issue with the available TV windows or selection order. Based on the open telecast windows, there are three telecast windows all scheduled to run concurrently (all times PT): 5pm ABC, 5pm Pac-12 Networks and 5:30pm FOX.
Have FOX and ABC had concurrent Pac-12 games at night? Kinda. Once again, all times Pacific:
- 11/24/2012, FOX had UCLA at Stanford start at 3:30pm and ABC had Notre Dame at USC start at 5pm.
- 11/30/2013, FOX had Notre Dame at Stanford start at 4pm and ABC had UCLA at USC one hour later.
As you probably know, FOX broadcast network has to air four Pac-12 games in primetime and they have yet to air one. They also missed the target of eight Pac-12 games on the broadcast network in 2013. If they are being asked to give up their window, let's say Pac-12 Networks airs three games this week, FOX, for example, might need to figure out where they can add a telecast window at a later date.
2) Rosh Hashanah, which started last night and ends tomorrow. I have seen TV announcements come out early because of what I assume was the observance of a Jewish holy day. One example was in 2012. Rosh Hashanah started on the evening of Sunday 9/16/12 and several announcements came out on Sunday mid-afternoon for games on 9/29 and the only connection I could draw was that it was Rosh Hashanah starting that evening. Maybe someone involved at one of the three Pac-12 television partners or the conference office is unavailable. Look no further than last night's Cowboys game, where Brad Sham did not call the game on radio for Dallas due to observance of the Jewish New Year.
3) An Arizona school is being asked to bite the bullet and play a late afternoon game. They don't like playing in the heat in September. This coming week, the two schools are both at home, but Arizona St.'s game was moved to Friday night in the spring, possibly to overcome an issue where both would have been televised by, for example, Pac-12 Networks with a preference for the same time slot.
Something else could be up that I'm not putting a lot of stock in (regionalization or reverse mirror with TCU at Texas Tech? Where does the other game go? F/X?). The conference's silence is a bit odd. I'm sure everything will sort itself out.