But the movement is cultlike, if you look at descriptions as to how cults work it is fairly obvious. RedToothBrush (think that's the right handle) has written some excellent posts in the past about how cults operate and it totally ring true. The only thing that transactivism does that most cults can't is to preach at state schools (with the sanction of the state).
Ally I don't think you are being quite honest with your categorisation. Your first statement is the sort of convoluted speech that I think gender critical femionists are being forced to make:
'[X transwoman] has said [Y] on Twitter about [Z]. I do not believe they understand the impact of [Z] on women because [eg they were raised with the benefits of male socialisation/they do not have the same reproductive issues as women/they are likely to be more physically able to defend themself from men compared to women.]'
where for all the text in [] one would normally say [they are a man] or [they are male] or [they are not a woman] but feel that this might be deleted and so can no longer be said without risking suspension.
I agree that the second statement might well be deleted and count as a strike:
'Look at what [X transwoman] has said on Twitter. He is so stupid. Did I mention that he is biologically male and always will be?'
The question is on what grounds. Is it because of the 'he', because it contains a personal attack 'stupid' or because of saying that X is 'biologically male'? or is it because X is likely to be tracking any comments that use their name and will kick up a fuss about anything that isn't completely affirming? Would the revised statement below pass:
'Look at what [X transwoman] has said on Twitter. What a stupid thing to say. Did I mention that they are biologically male and always will be?'
That has no personal attack (at least in line with mumsnet's usual guidance that you can say that someone has said something stupid so long as you don't call them stupid) and does not use a pronoun a named transperson has rejected and states a biological fact which mumsnet has said also is permissible.
If it's not OK then mumsnet has become somewhere which is policing heresy (going back to the cult affinity there, although most cults are only able to police their own members) or has been forced to moderate as if it is in a permanent state of siege, in which case it's more like the [she who cannot be mentioned] days, in which case it would be good to have a list of those who are on the attack so that they can be refered to obliquely and not put mumsnet at risk.