Thanks a lot for the ideas and warnings, everybody! After reading your comments, @yanokwa and I got nervous about all the things we don’t understand regarding inactive users and decided to just unstage everybody with User.update_all(staged:false) and leave them active.
That seems to have worked well – community members are successfully claiming their accounts and not creating duplicates. I now see that those who haven’t logged in yet and posted to the old list within the last 365 days got a digest. I think that happened to just include our “introduce yourself” post so it seems to have worked out really well. Will update here if anything else interesting happens.