I think words like the "n" word are part of an issue that is not analogous to this, though some of the same underlying principles around group solidarity or boundaries of decency or boundaries of groups seem applicable to both this issue and that issue.

I think part of the reason people form groups that recognize each other as members should, when the need arises, meet in isolation from people who are not members of that group is so they can communicate and correct each other in ways that they understand among each other and they will be judges by their peers. You can call that racist or racism, fine but it goes both ways. That you can see the benefit, or perhaps only acknowledge some of the benefit, for one but not grant it for others you declare oppressors is on you. Luckily people can meet without your permission, just as people can meet without anyone else's permission-- or should be able to anyway. Attacks on freedom of assembly are not new, but are never right.

Do you endorse spaces for women but not transwomen? Oh, maybe you do not recognize how oppressed they are by you, the same way I do not see how the very real oppression caused by others was caused by generally poor and working class white or straight people just trying to live their lives under the same systems of oppression everyone else has tried to lived under, where the most common tactic is to divide us and conquer us along lines they and not us define. My blindness to my culpability in others oppression, something I've been assured of by others on occassion, does not give me the right to veto that group meeting without me. Your potential blindness to what another group needs or to their sense of oppression does not give you the right to veto their ability to meet in separate from outsiders.

Do you think transwomen should be allowed to meet among themselves without others? It does not matter if you, or I, would want attend such a meeting. If they can not meet along among themselves, they they would have to be allowed to meet among what ever group you or I would recognize they are not a legitimate part of. Else, they just would not be allowed to go to meetings but that violates my sense of freedom of assembly.

Maybe I take issue with the notion of a group being allowed to based only upon their shared sense of oppression. I have no idea what the Knights of Columbus are or what they do, but I can't see why they shouldn't be allowed to meet even if their exclusion of non-Knights of Columbus seems arbitrary. If I'm misreading your reasoning, I apologize.