You mean why change their artstyle in the former case, like how there's Chibi armored Samus in the latest Metroid game?
Why change Link to Toon Link? Why change Mario into a piece of paper?
And why change an artstyle to be able to have a different gameplay style, just like when Samus can suddenly fit into a ball?
I'm not sure what you were trying to prove, but comparing this to a different character design (like making Samus black or Link a girl) is pretty reaching...
So that goes back to what I was saying: is wanting Samus (or any other established character) to be black just some mean to go back on some black characters whitewashed at some point (but not in videogames)?
Well I added this to my post in the edit. Someone like Lincoln Clay in Mafia 3 has to be black for everything to work as it does. Being black is huge part of the character and themes of the game, not only the appearance. Nathan Drake and Samus being white though, is that crucial? What traits in their nature or their past couldn't be associated with people of color?
And people who are upset of whitewashing in movies are upset because it's a lost role for minority who are underrepresented. We don't have similar lack of white people.
But I do agree that better solution is to create new characters.
What's the point or the reason behind that?