moderated Re: #owner
My 1st comment is - I don't see how this post is "a suggestion for a new feature or improvement to the service" which is what the beta forum is for.
If you are seeking comment directly from groups.io, best to email support. If you are seeking advice from other group owners, better to discuss in GMF, IMHO.
This issue was discussed at length here.
My take is - hosting your group on groups.io does not directly encourage or support indivisible in any way. Your group's content is totally under your control within the terms of the TOS and your group will not see anything related to this other organization unless you post it.
If your group is already associated with indivisible, then you can obtain free upgrade offered by the owner of groups.io, Mark Fletcher. That's it.