No, this is not a joke. Such a tag has been officially added and is available in the general tag list.
Over the past several dozen hours, Twitch has added a dozen different tags. Most of them do not arouse any emotions. Let us remind you that tags make it easier to search for specific broadcasts.
Now Satanists will be pleased because they can easily find “their community”. At first, it seemed to be some kind of bug, but no, such a tag was officially added.
Unusual tag on Twitch
Most of the tags added a dozen or so hours ago concern consoles. However, there are a few that are completely unrelated to them. Among other things, “recovery”, “multiple sclerosis” and “satanist” tags were added, which raises many doubts.
People are a little confused about how to approach it at all. Some years they ask Twitch to add specific tags and they never get a positive response, and then there is such a situation.