A new, unregistered user showed up a few days ago on another Stack Exchange site. That user posted a question, and then, about an hour later, a separate, registered account posted a non-answer "answer" to the question providing what appeared to be additional information that should have gone into the question. I flagged the non-answer as Not An Answer (NAA). That answer was later deleted, and the question ended up being closed as a duplicate.
Suspecting that the second (registered) user was operated by the same person who created the first (unregistered) user, I flagged the original question for moderator attention for a possible account merge:
I suspect that this unregistered user is the same person as [user profile link redacted] , who recently posted an NAA answer to this question which appears to give additional details for the question. Could you investigate this for possible merging? – Robert Columbia Jul 8 at 23:25
My flag was declined with the following message:
declined - In order to do anything I would have to re-open the question and undelete the answer, which I think is more than I should do with the two different names.
I am not disputing whether this flag should have been declined or whether an account merge would or would not have been appropriate (I have considered raising this on the appropriate per-site Meta but right now feel that a single such declined flag is too minor for such an action), but I wanted to ask about the truth of the custom message that the moderator left for me here, and to what extent this barrier actually exists for moderators.
Is it actually the case that closed questions and/or deleted answers prevent or interfere with an account merge? More specifically, is there such a technical barrier (i.e. the merge will fail/error out/trigger missile launches/etc. if posts are not reopened and/or undeleted before the merge is triggered), or is merging an account that has not done anything but post low-quality content simply something that moderators do not generally care to do?