Well, yeah. That's kind of the point, though. Amazon did a great job of salting the earth RE: legit criticism.
I don't give a flying fart if there's a black actor playing an elf. What I would like to know, however, is if he's playing a white elf or if he looks to the other characters the same way he looks to the audience.
Like, in the olden days all the actors were men, so female parts were played by a guy. The other characters, however, saw a woman. They played their parts as if the dude playing Lady MacBeth or Juliette was a female. The audience sees a man while the characters see a woman.
Fast forward to RoP and Arondir. Does Galadriel see just another elven warrior or does she see the only black elf in Middle Earth? (If he's not the only one, I didn't see the 'blink-and-you'll-miss-it' appearance of another) If the character of Arondir looks to the other characters like any other elf, fine...whatever. Cordova's doing a fine job with the material he's given. It does kind of spike the "black elf" narrative, though. If the character isn't black, then we don't really have a black elf, we have a black guy playing a white elf.
If, however, he looks to the other characters like he appears to the audience then why hasn't anyone remarked on it? Even some little interaction like "Hey, Arondir, we don't see many elves from the lands beyond the Haradrim. What brought you so far north?"
It's just a thing that appears to be purposely injected by the writers to serve as a distraction and a buffer against criticism.