The only time it is ever NOT "necessary" to do a faithful adaptation of something is if the source material is BAD to begin with (or dead in some cases, which I guess goes back to it qualifying as bad), which in most of the cases we're talking about, it's most certainly not, and there isn't anything wrong with the way Wally West and CO are, in fact, they're quite perfect the way they are in many ways. And how does making Wally black make him appeal to a wider audience? As if a black person couldn't identify with Wally the way he is because he is white, or can NOT identify with a character because the character's skin doesn't match their own - that right there is absolute horsecrap, when people of all ages and ethnicities have identified with the likes of Superman, Batman, Spider-Man, etc, without physically looking like them, for decades. I identified with Static growing up even though I wasn't black. If making Wally (or Iris) black makes him appealing to black people, does he suddenly become not appealing to white people? Can you only appeal to one group at a time? Because if that is not the case, then Wally is already appealing enough to all audiences the way he is, and a change, black, red, whatever, will not "improve" this. There's just no reason for the change(s), period, other than just for the hell of it.