How about if the creators of D&D products simply don't include something that noxious in their games in the first place?
You don't need to worry about something that "might trigger something negative." You could simply use some basic decency to know not to include things like that in a fantasy game that's supposed to be fun for everyone.
I don't know why you are so focused on something that, A) no one is advocating for it being a good thing or an intrinsic part of the game or Dark Sun, and B) is such a tiny part of Dark Sun - and thus not even part of the fantasy game as a whole.
Name one person who has literally be killed by a fire-breathing dragon, or has been turned into an undead, or has been attacked by an actual goblin.
I'm not looking for metaphors here. I want to see the actual cases.
Because the origin of muls isn't a metaphor in-game.
Neither are dragons, undead, etc - they are literal within the context of the game. But that's not the point I was making. The point is that you cannot possibly make every single aspect of the game comfortable for every single possible player, not unless you completely sanitize it. And even if you want to make the default, general rules as comfortable as possible, why can't some worlds and/or stories play with darker, less comfortable material?
When you play D&D, you know you're going into a game involving combat and fantasy violence. "May include sex slavery" isn't one of those things D&D is known for. Nor should it be.
Except if you want to offer a wide variety of settings, none of which are required by everyone to play. Look, I don't care about whether or not sex slavery is part of Dark Sun. What I care about is that WotC retains creative freedom, to offer a variety of settings and stories. I don't even particularly care for "edgy" or "grimdark" fantasy, but I do care that D&D is a game that can explore a variety of types of fantasy.
To the best of my knowledge, D&D hasn't included torture instruments in their equipment lists. I mean, I know that whips are weapons, but I certainly can't recall them putting a gp value on The Rack or The Pear or The Iron Maiden. Does the lack of official torture instruments bother you? D&D also doesn't generally include rules for things like syphilis or cancer (the odd prestige class notwithstanding). Does this make you think that D&D is going out of their way to "avoid triggering people"? Do that also make you think they're following "unreasonable restrictions as to what can be published"?
If not, then why is it so important that they include sex slavery?
Or, you can do the simple thing and change the origin of the muls. After all, no other species in D&D is created solely by forced-breeding for the purpose of creating slaves. Even when orcs were at their worst, it was never assumed that half-orcs were only the result of rape.
See above. But this illustrates the type of conflation you are continuing to make, that
@TheSword pointed out: there's a huge difference between including torture instruments in the core rule book and muls. Not only are muls not always the result of sex slavery (as someone pointed out), they are one race in one of many settings. Again, it isn't important to me that Dark Sun includes sex slavery, but that WotC feels like they can publish a setting like Dark Sun that incorporates such elements.
Aaaand here's where I'm done with you.
Exposure therapy, like all forms of therapy, require consent on the part of the patient. The person has to agree to be exposed to the thing that traumatized them, and the person who is administering the therapy has to be an actual therapist who knows what they're doing.
A DM is not a therapist. And the player isn't consenting to therapy; they're playing a game.
And not everyone who doesn't want sex slavery in a game has been traumatized in some way. I've never been sexually assaulted or abused. I don't want sex slavery in my game.
I addressed most of this in what I wrote, but you twisted it anyway. I realize that D&D isn't therapy, but you're missing my point, which is that experiencing uncomfortable things isn't always or inherently bad for you.
And the consent part is a total red herring. No one is forcing anyone to play D&D, to play Dark Sun, or to play a mul - not to mention to play a mul that is the result of sex slavery.
p.s. I don't want sex slavery in my game, either. I never bought the
Book of Vile Darkness or the erotic fantasy one, nor have I ever played an evil character (except on a one-off, and I didn't like it).