I don't know why people think the Pac 12 hockey conference is going to start over night because Arizona State is going NCAA D1. As of right now only one other Pac 12 school is being discussed about moving up and that is Arizona, I think that their ACHA division (WCHL) would make a move before any other Pac 12 teams do outside of Arizona and Colorado ( WCHL teams: Arizona State, Colorado, Colorado State, Oklahoma, Central Oklahoma, and Arizona). If Pac 12 does start and Arizona State leaves the NCHC the NCHC could do a NCHC/Pac 12 Challenge like the B1G/Hockey East Challenge. The WCHA did the same thing when Hockey East started.
I don't see the B1G ever adding schools form other Power 5 conferences because the B1G isn't going to share revenue with/or broadcasting on other Power 5 conferences networks (SEC Network and Pac 12 Network). Schools like Arizona State, Iowa State, and Alabama has only two options the NCHC or the WCHA.
I wouldn't be surprised if NBC is trying to get NCHC games on NBCSN, North Dakota gets talked about during NHL games and everyone knows Pierre McGuire wants NBC to go to Grand Forks to show games. The CBS deal handcuffed the NCHC and now the NCHC is seeing opportunities to get Fox Sports. You can thank the B1G for Fox Sports getting NCHC games on Fox Sports North. When it comes to ESPN showing games, it doesn't look good for ESPN showing games at mostly empty arenas and it's not going to get the casual fan to tune in and watch a game. Have ESPN come to Grand Forks or Miami and have a full arena on TV when you can hear the crowd get into the game.