I'm not denying that the history exists. I just don't think it's particularly relevant here.
First, Fantomah-as-Egyptian is not "black" as usually understood, she's an ancient Egyptian. The Egyptians were a semitic people, and as depicted in their own art their facial physiognomy was not (usually) markedly different from that of "white" people. In modern depictions, including in comics, they're usually depicted as European- or Arab-looking, with light brown or olive skin and with black hair.
Secondly, as I hinted at in my previous post, I find the idea that chalk-white rather than black hair could be considered a tweak to appeal more to white people bizarre. White hair is considered a sign of old age or poor health (including poor mental health) in our culture, while black hair (on white people) is somewhat unusual but not unheard of, and often considered attractive and a sign of strength, virility etc. (And many superheroes consequently have black hair, including Superman, Batman, Wonder Woman, etc.)
Thirdly, I think there's a fundamental difference between creating or using a black or other "ethnic" character while toning down their racial identity to go down more easily with white readers on the one hand, and re-conceiving an existing white character as being of a different ethnicity while still retaining certain identifying characteristics of the original on the other. One is whitewashing, the other is "partially see-through blackwashing".
Finally, I don't think I was using any strawmen. Every example I gave was a direct quote of something someone has said in this thread. And yes, I think taking all these sensitivities together, we're setting up a standard where artists aren't free to take any chances, to be bold, or stray at all from the tightrope of political correctness. And that means that non-white characters can only be depicted in the blandest, most boring way. Who does that serve? Even knowing the raw history that motivates the sensitivity, I would rather cut artists some slack, and try to distinguish between what is expressly racist, what's well-meaning but stereotyped or somewhat patronizing, and what simply expresses the perspective of the artist's background (e.g. a story set in some suburbs may not have any black people).