Why is it important, though? Why is Ciri's ethnicity specifically as important to the substance of the character or story as being black is to Shaft, who is explicitly a blaxploitation character, for example?
Sure, it doesn't change anything for me, at all. Why would it? Like ponder mentioned with James Bond - why on earth does it matter if he's black? It changes nothing about the substance of the character or story.
The Heimdall thing actually proves my point.
Basically nothing about Marvel's version of Norse mythology is accurate. They're aliens with advanced tech, not gods.
Here's a list of stuff that's totally different to the source material.
So why is them changing all this stuff not an issue, but Heimdall being black is? Makes no sense. Not to mention how all the Marvel movies have changed the characters and stories from the comics. Come to think of it, basically all adaptations of games/books make big changes to source material characters, storylines, settings, etc. Even Beyond.Celsus mentions in a previous comment how they've already confirmed this will be a "completely new Geralt, separate from the one in the games." So why is that change not an issue?
With Malcolm X, the character's race is central to the character and the story. That's different, imo. In the same vein a black Abraham Lincoln wouldn't make sense, either, for example.