I've been complaining about the addition of that French upstart Lancelot since 1066 but nobody seems to share my concern.
Except that’s not really equivalent, as that’s an addition to a story, not a fundamental shift in the setting of the story. They didn’t just suddenly change the setting to, I dunno, Japan and make Mordred an upstart daimyo, replacing the lady of the lake with something from Japanese folklore.
The deadlands example also is not equivalent as it’s based on real history, leading into alternate history that had/has painful real world connections and consequences.
This whole concept is absurd. It’s like saying, do you know what? Me and some friends, we are new fans of this Star Wars thing, but can we get rid of lightsabers? And the whole force thing, and space ships. Oo, and could we add elves and dwarves to it? Don’t complain, you’ll still have the original movies, let me and my friends and new comers enjoy Star Wars for what it is now, stop gatekeeping us!
Its quite simple, if there is a setting that intrigues you, but has elements that you don’t like or make you feel uncomfortable, you have several options:
1) Don’t play it! Nobody is forcing you to!
2) Play it, but change the bits you don’t like at YOUR table. Don’t demand the baseline flavour and setting be customised to your whim.
3) Create your own setting, stealing liberally from the bits you do like!
Honestly, demanding a reboot of Dark Sun and expecting the removal of restrictions and elements that MAKE it Dark Sun would be as ludicrous as releasing a well established horror setting and demanding that you don’t scare players, or ignoring the inbuilt feature to add mini settings and lords to customise it how you want and just completely change existing things in there arbitrarily instead. It‘s completely…oh...