Migration stubs are autodeleted after 30 days, and if a tag is only in use on deleted questions, it won't be available for use for other questions.

A later feature request was implemented that prevents tags with tag wikis from being subject to this deletion script. The source needs to be updated with information from meta.stackexchange.com/questions/127700/… (it's marked status-completed).

Also, doing what you want will need a mod to reopen the question, edit out the text, and then reclose the question. These older questions have a different close reason internally on them ("exact duplicate" vs. "duplicate) and this will remove the older close reason and replace it with the new one.

You add an HTML comment to the post to bypass the 6-character restriction, and put in the edit summary to have reviewers "Improve" it and remove the comment. Or, you flag for moderator attention explaining the situation, linking to the appropriate approved tag cleanup request.

@Ramhound Or alternatively, just click to see vote counts (if you have 1k+ rep), as those are based on actual vote count and not displayed vote count.

There exists a request to increase the rep needed to create tags.

Oh, and if a certain tag gets cleaned and recreated several times, it should be blacklisted so as to prevent future recreation. This, I think, applies to the company tags.

@OliverSalzburg If a deleted tag removed as per a tag cleanup request gets recreated again, should we tag the older question as planned again, or should we have to create a new request for the same tag?