I don't know if it's part of the same phenomenon but it is kind of creepy, like realizing you're surrounded by replicants.
LLMs are not alive, of course, nor will they be. But personally I think that artificial sentience counts as a distinct lifeform just as much as aliens would.
But I think it's pretty unambiguous that there's a difference between "person" and "homo sapiens". That's why people are using the term human to disambiguate. Our current level of "AI" are not persons, but an artificial sentience would most certainly be, as would be aliens, and certain animals on Earth once we learn to communicate with them.
I also don't recall seeing people use "humans" excessively, or in a way that sounded off to me.
Different people can interpret the same social phenomena in different ways and subjective experience can differ between individuals. That your experience differs from mine doesn't negate mine.