At my local group, we don't discriminate by operative status, etc.
We have pre-, post-, non-op, genderqueer, significant other, and even the occasional "friend of trans" at our meetings.
At a certain point early in the group's development, there was a mass exodus of the "friends and allies" crowd at the actual meetings for one set of reasons, and some of the trans folk who can't stand being around trans folk for that reason. But in a general sense, ours seems to be a pretty healthy, fluid group.
I've seen as few as 4 show up, and so many that seating was an issue.