Upon checking, the channel is available on our channel store online. For clarification, is PAC-12 already installed on your Roku device but when you access it, it says "Coming soon"? If so, removing then re-installing it may help. Make sure to restart your Roku device before adding the channel back in. That step is crucial when performing the troubleshooting.
Here are the steps you can follow:
Remove the channel: Highlight the channel tile on your home screen and press the Star button to open the options menu. Select Remove channel and confirm.
Restart your Roku device: Restart the device from the settings menu. Go to Settings > System > System restart > Restart.
Re-install the channel: After your Roku device restarts, visit the Roku Channel Store and add the channel again.
Yes, I had previously installed PAC-12 channel (online). I followed your instructions for removing/reinstalling but I get the same results: "Coming Soon". If I press 'OK' it comes up with instructions on how to "cast live tv & videos from the PAC-12 App.