The idea being that everyone and everything is fair game and it means that whoever you are it means someone will come around and make fun of you as well and being okay with that.
This, of course, ignores power dynamics completely. There is such a thing as punching up and punching down. And, realistically, what we're talking about here is the right for white guys on the top to punch downward with the same stale, bigoted humor they have for a very long time.
This straight white man might almost be a monster of mythical proportions when you read what evil and ill intend is ascribed to him.
I think my point is made perfectly when a ton of white guys descend on me in huffs and puffs of hurt feelings and carefully written essays for making generalizations about them. Everyone's supposed to snuff it up and take the offense in silence except them. Come on guys. I'm only being "edgy".