Here's the difference. If someone makes a slavery joke it doesn't impact your life, or enforce stereotypes that can lead to harm, or invalidate your identity.

Trans women already have to deal with people trying to exclude them from women's spaces because "it could just be a man pretending", or going to the restroom in public because "it's just a man trying to perv on women".

Jokes that are like this cause actual issues for us because some people already think this happens. The intent doesn't matter or make it not problematic.

The attack helicopter joke is literally "haha, look at these made up genders". The joke is invalidating non binary people, and is transphobic.

Just because you're a minority doesn't mean you get to decide that it is okay to joke about things for other minorities.