Hub Community without Premium Account?

[KansasDASC]

Hello, we have a ArcGIS Hub Basic setup, but we just noticed that in the Overview section of the Hub site, there's a Community listing of 200+ members. We don't have Hub Premium in our organization, so what are these accounts? Are they being used against our total user accounts in our organization subscription? What user roles are they? I've tried Googling this and Esri keeps pointing me to Hub Premium access, but again, we don't have that.

There are references to links/logins in our Hub site, but they require a Premium account to login. Can anyone point me to resources or answer where these Community accounts are coming from?