I just switched to Xfinity/Comcast yesterday (in large part to get the PAC12 but other issues as well) and I have checked every Fox channel and have seen the Utes game listed yet.
I am new and learning the differences but I have also setup favorite teams and it shows the next game the Utes play is Washington, so I do not think my guide has been updated as of yet. Even stranger yet, yesterday I believe the station I saw it listed on was one of the PAC12 channels but I would have to go back and find it, if it is still even listing it on that channel. It also could have just been a replay of on old game and as the PAC12 channels do, do that.