I think I found the answer on an earlier thread:
So if you leave the members behind during a transfer, that message will no longer be associated with any "posterid" within groups.io, because such an account does not exist. For example, you won't be able to "find" other posts by that person by searching on "all posts by this member." But the text metadata?will remain in the message base, whether the associated member is migrated or not. Specifically, the from address is not munged or changed to "anonymous."
Source: /g/GroupManagersForum/message/19979
So I think the answer is, yes it will show the original poster addresses / names but they won't be associated with the user on Groups.io and even if that same user gets added later, they still won't be associated.
I don't think this will be a problem for us.
Thanks,
Su
