Not true at all. There are even cons on here that’ll argue Hitler and Mussolini were left-wing socialists. Rand Paul argues that Nazis were socialists in The Case Against Socialism.
I don’t see antifa embracing militarism, nationalism, antisemitism or anything of a corporatist character. They are fighting groups like the Proud Boys and other fascist and white nationalist groups to get them off the streets, and I thank them for that.