I get that. There are a certain category of shows from Hollywood that I have avoided completely because reasons I'm unable to explain here.
But are you equating slavery in RPGs to black trauma? Mindflayers with their Gith, Giants with their Dwarves, Drow with their slaves...etc
My perception of slavery is, and this may seem brutally cold, a natural evolution of society.
And the reason I've come to this conclusion is because of our disappointing human history. So it's not a far stretch to say slavery would likely exist in a fantasy setting especially when the physical differences (nevermind cultural) are far greater than skin colour.
To answer your question no, I'm not. Right now I believe there is nuance and context to issues so I am not claiming every instance of slavery in D&D can be equated to black trauma. As it sits now the references to slavery are so small and scattered they can easilly be overlooked and ignored for any particular game and are not in and of themselves a necessity to play D&D.
That said... My argument from the beginning of this has been that I can understand and I empathize with WotC finding Dark Sun problematic and choosing not ot publish it (as opposed to those who can't seem to see what the problem is or think WotC is somehow wrong for the choice)... and not just for slavery, but that's been one of the things that instantly stood out to me as a black American. Why? Because by publishing Dark Sun WotC is by necessity putting the trappings of slavery and all that entails (as well as many other problematic setting elements) front and center for 12+ year olds to utilize in their games. I don't care how well the treatment of said issues are, you put them in the hands of pre-teens... hell even some teens and up and you should expect a lack of maturity in dealing with said issues.
Now in America (not sure about other places) antebellum slavery has been so intrinsically made a part of black people's identity (especially through it's constant focus by American media) that when the said pre-teen or whoever decides slavery is funny, a joke should be made about it, let's act it out, etc. it will...
1. Inevitably fall first on the black kid or kids sitting at the table as that will be the most natural target for a slavery joke... or the most obvious person that should be a slave vs. a templar will be the black kid playing and so on.
2. Black people are already a rarity in this hobby and basically non-present in parts of it. I enjoy Worlds Without Number & OSE but there are nearly no black people in the OSR scene, even among those who have stepped into gaming the OSR is found distasteful for the most part because of the reputation of many of it's players and creators...and this is something WotC doesn't want for their brand... something I don't want for their brand and Dark Sun has a real chance of being the product that can cause some to view D&D with the same distaste.
Also I know I am talking about slavery in Dark Sun from the PoV of a black American man... because I am one but these sme concerns apply to black women, daughters as well as just girls and women who play. I just don't have the faith that some do in all gamers treating the setting elements of the game, as well as the people they are gaming with, with the respect and gravity necessary for this not to become a cluster.... for WotC at some point.
As to whether slavery would exist or not in a fantasy culture... it's fantasy, whatever you want to exist is in it. You can justify it however you want but it's all made up.