Hastur's comment on the question raises another point that's worthy of coverage in an answer. As long as a tag exists, it has the potential to be used. If it has no definition and is ambiguous, Murphy's law says it will not only be used, but misused, creating work later. Users don't always read the excerpts, but to the extent they do, it helps to have one, even if the tag is temporary.
Some of the manufacturer meta tags have been edited to state that the tag is deprecated and not to use it. At some point, the tag will be gone. In the meantime, the edit is useful. The manufacturer tags with no deprecation warning are continuing to pop up on new questions.
As both Hastur and Raystafarian described, removal of a tag should be a separate action.
Time Consideration: If a tag has any significant number of questions, the protocol for tag cleanup is for a public comment period of typically a week or more, so the tag will typically be around for awhile and subject to the consideration mentioned above.
The example here is sort of a special case. If a tag is blatantly bad (and there's disagreement over whether this one was), and has only a couple of questions, users with enough rep to edit can (and do) just delete the tags. In that case, the only justification for the edit is the one in Raystafarian's answer.
The empty tags are deleted by the system in 24 hours. If you have less than 20K rep, you can only vote to approve the tag edits, and the edits need to attract sufficient other voters who agree. So, it's a race to the finish line whether the editor will even get the rep unless you purposely delay deleting the tags.