I'll share some more thoughts I had from a personal perspective. I think that it's positive when characters like Superman and Wonder Woman are left ambiguous enough to be accessible visually to non-white minorities.
Growing up as a Latino kid in the 90's, my most identifiable version of Superman was Dean Cain, who is mixed and has Asian ancestry.
Although I'm not the darkest Latino, I had absolutely no pause seeing myself as Dean Cain's Superman because of his features and dark hair, dark eyes, and tan skin. Similarly, when the Animated Series came out, they had both Jor-El and Clark/Superman looking pretty damn dark next to other white people, with dark eyes.
So, I never had to think twice and "pretend" that I looked like Superman while wearing his costume for Halloween (and every day after school in the 3rd grade for like, months...) because I just did. In my head, if not in actuality. I wasn't some super race-conscious kid who constantly thought about my ethnicity, but I didn't have to do that 2nd guess that many (not all) kids consciously or subconsciously make when embracing a hero. It was effortless, the way it must be for most white kids and most heroes. My Latina cousin, who isn't much of a comic book geek, made an excited facebook post about little hispanic girls being able to see themselves as Wonder Woman when the trailer came out. She's much darker than Gal Gadot, but it's close enough that it makes a difference. I'm not saying it works for everyone or every race, but it worked for me in a way that didn't throw off the majority white fanbase.
My anecdote simply serves the argument that the more universal-looking icons like him are, the broader the audience that can relate to him, and the more of a global hero he can become in-universe. I love Reeve, Cavill, and many blue-eyed pink Supermen of the past. But I always think to myself, when he's saving some little black girl or a South Asian boy, that it's just a little nicer when the colors don't clash so harshly. And whenever I see it in comics, I think to myself, that just looks right.
But that's not to say that comics shouldn't work to keep diversifying comics with fresh and committed takes on minority characters, or that subtly racebending Superman is the limit and that Superman himself can't be reimagined as a different color. Just saying, a little sun goes a long way.