In fairness, Xbox One accurately describes the original vision. It was supposed to be an all-in-one device for games, TV, even apparently the Alexa functionality we now see everywhere. It was supposed to be the living room box.
Obviously, reality went a very different way, and we now have a name that doesn't really mean... anything.
Series X on the other hand... It sounds nigh-on identical to One X, to the point where even I use the wrong one at times, and just has no flash. It's awkward to say and doesn't really have any kind of intent or purpose behind it.
The only thing that will save it, is if there's a Series S. That would mean the name of these new consoles is indeed just Xbox, and the Series stuff is just for different models.