Now that our community is named Community Building, we ought to revisit the community-building tag. (SE doesn't even allow creating a tag that matches a site's name; this is only able to exist because it predated the name change.) What should be done with the questions currently using this tag? Do we need to create one or more new tags?
Just as you said: it's standard procedure to disallow a site name as a tag for that site, but that didn't happen here because CB wasn't this site's original name. Tag is now burned and blacklisted. There's nothing in the untagged list, so hopefully that is the end of that.
I just went through and re-tagged any questions that only had the community-building tag on them. I propose we simply nuke the tag now.