It can be about toxic masculinity, racism, misogyny, homophobia, whatever. I think that these are all real things and important to address, but participating in make-wrong and alienating fellow leftists, while completely dismissing non-leftists as inhuman, is self-defeating.
I like the idea of “call-in” vs “call-out” culture. By inviting other people to the table in a private setting and opening a dialogue to discuss the experiences of marginalized people - or any individual’s need for accommodation - rather than scolding people in public for not adhering to in-group norms that may be completely opaque to outsiders, you change the dynamic. And just by relating to people as people, in more intimate and personal settings than online anonymous forums or a standoffish workplace culture, we take down some of the walls that seem to separate us.