Gender Isn’t Ternary Either

Within the queer/trans community, we have no shortage of genders. But to the outside world, the frontier of trans inclusivity is all about pronouns. Facebook now recoginzes three genders: she/her, he/him, and they/them.
It is anachronistic at best to apply the label “cisgender” retroactively to people who were historically considered (or self-identified as) transgender. When our present-day ternary is applied in full, and every queer in history branded neatly as either “cis” or “trans”, it becomes violent: When we erase the self-identities of historical gender deviants, we not only misgender them, but we deprive each other of access to complex histories that cisheteropatriarchy has already worked hard to erase.
Who got left out in the rain when we closed the transgender umbrella, and how do we construct the tools we need for all of us to weather the storm?