Tweet saying:

If you encounter a guy dressed as a girl "as a joke" this Halloween offer them transition info and be welcoming because if it's an exploring trans girl, it'll be helpeful and if it's a shitty cis dude, he will be furious. It's a win/win.

As many other comments here (really liked the way /u/opperharlie put it) I think it's a shitty take. First of all, there is drag which is totaly valid. But I think crossdressing in genereal -if it's not done derogatory (which I never experienced)- is a totally fair costume. I am certain I am cis and have dresses feminin for costumes a few times and don't see what the problem with hat is.