Odd to hear that "Kang" is becoming a slur against African-Americans, given that Lee & Kirby's choice of Kang as a villain name, like Star Trek's use of it as a Klingon name in "Day of the Dove," was probably influenced by the pervasive Yellow Peril trope of Asian-coded villains, like Fu Manchu and Ming the Merciless. Comics of the day had no shortage of such characters -- see the Mandarin and Fin Fang Foom, for example. So even a villain not specifically intended as Asian, like Kang, might still be given a Chinese-sounding name because it would've conveyed a sense of exotic menace to the (white) audience of the day.
I'd figured that the Kang character was far enough removed from the name's possible racial-stereotype influence that it wouldn't be an issue today, especially with a non-Asian actor playing the part. So there's quite an irony if it's become a slur from another direction altogether.
Of course, they could always just bring him back and call him Rama-Tut or Immortus, I guess.