As a gay man, I feel as though this Instagram post is a little misguided.
"Cis dude" also includes gay men, so they should have been more specific if they meant straight dudes. If they did mean to include gay men in "cis dude" then it's hurtful because it's as if cis gay men aren't "queer enough" to attend.
An event like their's would seem to be about inclusion but there is a vibe of exclusivity especially when there is a check list you have to meet if you're not part of the lgbt family.
I 100% understand someone's deep seeded anger and frustration towards a group of people who have privileges that you feel you've been denied. I just think they should have been more tactful when making sure that those who attend are respectful.