We’ve recently made the AI bot module from our AI plugin available to all plans on our hosting. 
These three users are the friendly little chaps who would be dishing out the AI advice once you enabled it and added in the relevant api keys (Discourse AI - AI bot).
However, as Moin points out, we’re now thinking it would be better to defer creating them until the AI Bot module is actually enabled and configured by site admins. 
That’s still a work in progress change, but hopefully we’ll have that sorted soon. 
Sorry for the scare. 