I'm not sure what you mean by "open source orgs" or why you felt you needed to create a throwaway account to leave the comment. But, in general, "internal communications channels" on open source projects are something of an anti-pattern. Certainly, private board member (or other person-to-person) communications can be necessary but what you're describing sounds like an unhealthy atmosphere in general if there's a lot of contentious backchannel comms.

By "open source orgs" I mean entities such as all the non-profits which host/support open source projects.

You're right about it being unhealthy, unfortunately. It might be for the best if it dies and is replaced by something else.