Well, I mean, I don’t disagree; those are all racist terms. The dehumanizing aspect of those terms (and more generally with racism) is that they are reducing a person to their physical characteristics. “They’re black” is different from “they have a dark skin color”. One is talking about “what someone is” holistically (dehumanizing), while the other is talking about a specific aspect of their physical appearance.
That seems a bit of a stretch. The idea will evolve into, “Since racial labels are bad let’s just ignore them altogether and be color blind”. But we all know that’s not how the real world works. Three male programmers with same qualifications, the black man is going to have a different experience with the police than a white man. And the Asian man is going to deal with different stuff when it comes to dating.
I don’t necessarily disagree with this comment but I also think the things you mention are examples of how society-wide dehumanization can affect real-world decision-making when it comes to certain demographics.