The content channel can't save the notes. Sun Valley uses message notes in the Subplash app and also a PDF of the notes from the Rock content channel. They need to do something similar with the Celebrate Recovery content channel.
It's one of two things (I think).
They have a custom hybrid Subsplash app that is driven off of some custom webhooks and we would need to do some digging to find it.
OR they manage this from their Subsplash Dashboard (this would be my guess) and somehow Subsplash helped them to drive their messages from Rock?
(Submission largely influenced by information from Steven Shulte the Great and Mark Lee the Great)