the trans (otherwise non-gendered) spaces i've tended to occupy have been trans fem dominated... which is cool but eventually can feel kind of exclusionary to like... share a space? because i'm trans masc and not necessarily looking to get the good girls posts or the girl euphoria posts etc
so it's not really like a... oh being a trans fem is triggering... it's just an acknowledgement that not everyone in the space is. but i get feeling some friction about it. maybe it helps to imagine the equivalent trans masc post? "girlmoder or not, you're all handsome and valid"... and you can decide for yourself if you feel like the "cw: assumes viewer is trans masc" is warranted
but that's what i understand the origin of the rule to be, and for what it's worth, it does make it a lot more pleasant to be around for me