This is just like DiffusionCommitBranches but instead queries tags
This is fine technically, but I'm hesitant about introducing it because it makes the issues in T6522 worse in some sense. That is, this field really means something like:
Tags... that the commit is tagged with when it first appears in the repository
...which isn't very intuitive, and probably less intuitive with tags than with branches (you would expect tagging something with release-3 and then pushing the tag to trigger the rule, but it won't).
I don't remember the original discussion from IRC at this point, but I think it was something that might be resolved by forking (T10691)?
Generally, I'm not happy with where T6522 is right now and don't have a way forward on it yet. I'd like to have a clearer path forward before bringing fields like this upstream, at least without a specific use case which is strong enough to justify the greater peril from T6522.