See also About unnecessary tags and the minor edits adding them for my list of low-quality tags.
I think the following changes might either: Help prevent tags like these from flooding the minor edit reviews, and wasting space in the 20 allowed reviews per day, or: prevent such minor edits from leaking through to be accepted. There might be some flaws in these suggestions, but perhaps it might help to just put this out there.
I am aware that the bounty on this question is looking for sources, and I only have one, but I think this might be useful to share anyway. I am not sure about if these are good enough suggestions to be feature-requests on their own though.
Restricting the usage of tags
Perhaps this is a slight bit radical, but I think this might just work. What if, before using a tag, it needs to have at least 2 followers? That would prevent the creator of a tag from using it before anyone else has shown any interest in it at all. It's not hard to get 2 followers if the tag is actually a useful tag, but pointless tags that are pointless won't get anybody else to use it, preventing the creator from using it too.
I can't think of any (significant) downsides to this*, since it would still allow anybody other than the creator of a tag to use a tag anywhere he wants - all he has to do is add it to his favourites if he is the second person to find the tag useful. After somebody else has shown interest in this tag too, the creator will then also be free to use the tag anywhere.
**See Troyen's comment for a downside to this suggestion for the smaller SE sites*
Ability to flag tag wikis for mod attention
As far as I could see, there's no option to flag tag wikis (I'd guess because they have to get approved by 5000+ rep users in the first place). I do think it would be useful to be able to flag these, so that we don't have to create list-your-bad-tags posts on meta.
Review audits for minor edits
Part of the problem is also that suggested-edit reviewers are letting these edits through. Currently, the only suggested-edit review audit I've seen is audits that were mainly insertion of gibberish. This seems to focus mainly on bot reviewers, since most humans that are paying attention would pick out most of those edits (not all, but most).
What I think is that perhaps if there are some audits that simulate edits adding very minor tags, such as the ones listed here, these extra audits would help the reviewers spot these minor edits more often, and therefore prevent these kinds of minor edits from being accepted so often.
More restrictions on tag creation
I have no idea why, but for some reason creating tags without needing them reviewed is allowed from 1500 rep, while editing tag wikis without needing it reviewed is restricted to 5000 rep. I think this allows for the creation of too many pointless tags way too easily. Raising the ability to create tags to 5000 rep too might help prevent pointless tags from being flooded.
Special case for approving/rejecting tag edits
Reviews for edits that only added or removed tags should be counted via the same system as foul balls in baseball: They do count towards the 20 edit reviews per day, but after those 20 edit reviews, you can still review them. Alternatively, they could just not count towards the 20 reviews per day, since they're so minor anyway.
More checks for commonly rejected/too minor-editing users
(not entirely sure about how this currently works, but I'm getting the impression things might be lacking)
I'm don't know how often this happens, but I think users whose edits get rejected should have their edit-suggestion rights temporarily revoked if they make too many of these minor edits. That would prevent the users that are mainly adding pointless tag wikis (like those who are trying to raise their reputation easily) from doing more harm than good with their edits.
Perhaps there could also be a list for moderators to see what edits were tag-only edits, to make it easier to find users who tend to make such minor edits a lot. Perhaps to discourage these massive tag-editing sprees, there could also be a reputation penalty that would revert the reputation gained on approved edit suggestions. This would be in response to Pëkka's concern:
Short on rep? Find 1000 questions, no matter how old they are, and enrich them with some bullshit tag like
div. Get them rubber-stamped by three reviewers and enjoy your free rep!
—Pëkka's bounty message on this question
Stop awarding +2 reputation for approved tag-edits
I think adding tags might just be a too easy way to get cheap reputation. Exactly like Pëkka said in the above quote, getting reputation is really easy if you just edit a bunch of tags. Basically every single tag-edit is too minor, except when the edit is something like removing completely irrelevant tags, or adding vital tags to a question.
The impression I'm getting though, is that most edits that only change the tags on a question are way too minor to warrant the +2 reputation. I do get the reputation for edits that actually improve something about the post, such as formatting or grammar mistakes, but in general, I think tag-only edits are just way too minor to be worth 2 reputation points (keep in mind, 2 points is the amount you lose with a downvote, to put it into perspective).
A list of forbidden tags
I'm not sure if this would be possible, but if it is, the following would probably be useful: Here on meta.SO, there are mod-specific tags, such as
status-completed. How about we create one tag, for example "
forbidden-tag", and then make each forbidden tag an alias of that one tag? It seems to me this would be a lot easier than having to monitor all the bad tags that should stay deleted. The tag won't be used on any questions, so it would only appear on the bottom of suggested tags to add to a question, and because of that users won't see
forbidden-tag pop up unless you're specifically trying to add one of the forbidden tags.
**See Charles' reply to this for the better alternative.*