Not OP but I think they meant supporters of neoliberal economic policy and somewhat progressive social policies. "Liberal" like American liberal politics. The point being that they think they have good politics because they think trans people are people and aren't the kind of right wing fanatic we get a lot of. They're "left" to the extent that the American political spectrum allows for without understanding what "left" actually means, without being conscious of the overarching machinations that make then think their politics are good even as they continue to feed a system that intentionally blinds them to any honest criticism.