Oh, thank you. I’ve moved those posts into this topic now so we can have all that context here as well.
One thing we’re considering doing is to change things so that “reply” permissions are required to join channels. If we go that route, “see” won’t be enough to join (we may allow you to preview channels with “see” access, but not join them).
Perhaps that alone would address your use case?
I can see value in more explicitly configuring which groups auto-join a channel and making that an independent subset of which groups can access a channel as well…