I've been reading far longer than you've been in publishing. If you are reading a book written by a white author living in a white country, there is the rational assumption that the characters will also be white unless stated otherwise. Ditto for Japanese authors, Chinese authors, Russian authors, etc. If you are reading Tolstoy and the setting is Russia, you don't need to be told that the characters are ethnic Russians.
I suggest you try reading some books from non-white authors. White characters are very much described as "white" in those books.
Don't embarrass yourself by trying to pull rank over me. It serves no point other than to distract. Still, congrats on reading—though that's not the same as what I do at my job. But, no, I disagree with your premise. If I am reading a manuscript written by a white author living in a "white country"—as you put it—I, in fact, do not have a rational assumption that the characters will also be white unless stated otherwise. The only expectation I have is an author, of any ethnicity, to write well. Defaulting to a race is not good writing as per Aristotle.
The point here is emojis. And you've been very disingenuous in your posts. There are cartoon emojis and another set that appear more humanoid. Personally, I don't use emojis so I'm not very interested in the new set of emojis. I think emojis in general are a bit vapid since I'm old, ethnic emojis are even more so. Nonetheless, I can understand why nonwhites would want something more than white emojis.
If you're a graphic designer tasked with rendering more human looking emojis I don't think it's too absurd to include different sets to reflect the diversity of human beings.
But mostly, I find it highly disturbing you'd characterize the United States as a "white country." I suggest you take a moment and reflect on that sentiment. With that said, I bid you adieu.