I've seen a few people of mixed heritage post that they find the idea of dropping the "half" races as anything from absurd to offensive. While I think that I understand (in theory) why the naming convention of "half-x" to be less than ideal (the main point, I think, being "Why not the other half?" or "What about when the unnamed other half is not human?") I'm not sure that the solution "you only get to take after one parent!" is really ideal either.
What I have yet to see is any person of mixed heritage say, "Good thing they finally got rid of those offensive half-races!". I wonder if that idea exists, really.
Of course, it's also possible, I suppose, that the designers wanted to drop them for reasons other than the desire to remove offensive content, and that theory is just way off base.
Growing up, I always wondered what people thought I was. If I ask 5 people what they think I am, I will get 6 answers.
Then Obama became President, and I noticed something odd.
Everyone called him our first
Black President, conveniently forgetting his White half, and the fact that he was raised by his White mother and grandparents. This wasn't lopsided treatment; both the Blacks and Whites did this. It made me realize something; the world will see me as Asian and I learned to be okay with that. I remember a long time ago, in the late 90s, I watched an interview with Lenny Kravitz on MTV. Someone in the audience asked him what it was like to be half Black, half Jewish. He told them "My mom told me, 'son, remember that you are half-Jewish, but the world will always see you as Black'". That's just the reality of growing up mixed race in America to make one race the "dominant" one. Not all countries are like this, but the American psyche seems to be so conscious of race in the first place...even compared to South Africa. I've watched Trevor Noah say that he had a totally different experience growing up half Black in South Africa, to being half Black in America.
I'm 6' tall, and in my younger days, was a pretty big muscular guy. I think this throws people off to some degree. With Filipinos, if they just see my face on a webcam, they will ask me if I am Filipino (my mother comes from a contested region of the Philippines that is closer in culture, religion and language to the Malays, but it's just easier to say I am half "Filipino" than "half Bangsamoro"). But when they see me in person, they pretty much never think this. I've had Polynesians come up and ask me if I am Polynesian, and when I visited Hong Kong and Singapore, I had several people just automatically start speaking Cantonese, Mandarin or Bahasa to me including airlines stewardesses (ironically, no one ever just starts speaking Tagalog to me).
But if WoTC thinks they are somehow being politically correct, if anything, I would find that reasoning more offensive (if they actually are going to drop half ancestries and that's their logic behind it). It's like denying that admixtures happen and that there
are differences. My older brother and I are nothing alike. He got my father's face, and my mother's family's build, and I got the opposite. My brother can easily pass for 100% White and if he didn't say anything, no one would even ask (he's more White looking than George Conway in my opinion....and if you didn't know, George is half Filipino too).