This piece is full of the critical theory 'power is in everything' worldview, i.e. the 'postmodern neo-Marxism' Jordan Peterson speaks of. I don't see anything wrong with Arc publishing the Singal piece. I don't see anything transphobic, it's just a perspective. And most of the trans community probably don't want to be used by the critical theory activists to prove a point anyway.
The other problem with your argument is that you are taking Mamone’s side of what should actually be an intra-trans community debate, thereby helping to suppress the other side of that debate, as well as contributing to more conflict in the trans community. How’s that being pro-trans at all?