If someone creates a community for their XMPP project, that should obviously be allowed. But what about tangentially related technologies or XMPP-focused general discussion communities? Eg. would an IETF KITTEN Working Group community be disallowed because it’s not specific to XMPP (not that they’re likely to create a group, I was just trying to think of something tangentially related)? What about a group to discuss XMPP Security or XMPP UX that’s not specifically tied to a project or group? It may be worth us developing a policy on this early on to stop conflicts before they arise and to stop having to grandfather in to many groups if we decide later that they’re out of scope.
Seems okay to me, but I’d bet existing ones are already established and probably other instances will have a wider user base. But I don’t see any reason to forbid it, personally.