Looking up Zuby's antics, seems like he intentionally used "OK dude" to insult a transwoman. Misgendering people intentionally is hateful. Not sure where your confusion stems from.

This is after he tried to dismiss the legitimacy of trans people by way of entering a woman's weightlifting competition, claiming he identified as a woman while not out as trans. These dumbass shenanigans are consistently done by folks who "don't believe" in transpeople, or go the route of claiming they have a mental illness.

The rest of the world already cancelled transpeople before the phrase cancel culture existed. Give them a break already.