Yeah.... don't get yer hopes up too high... quote from the article:
“Immersive Player Names” may actually be a more accurate name for the feature. Giving consistent names to the empires in Humankind honestly turned out more difficult than expected, and we went through several iterations looking for a version that worked well in all supported languages. In the end, we decided to move the spotlight from the empires to the avatars themselves.
So, why is this important? Well, while changing and adapting your culture to the shifts in your situation is a core part of the Humankind experience, it could honestly get pretty confusing (as many of you were quick to point out). “The huns have declared war on me? The who? Oh, they used to be...” And referring to the other players as “the green empire” or “that pink $#?@!” isn’t much fun, either, and robbed the avatars of a lot of their personality, as they were just not very present while playing.
Now the game will focus on the avatar name for most interactions (with their culture usually added in brackets), so you should feel much more like you are interacting with the same leaders throughout your game, rather than a string of different cultures. You’ll probably notice this most with the various notifications, where you don’t get the benefit of seeing the other avatar as you do on the diplomacy screen. Now it’ll be much easier to keep track of who is who and what they’re up to if they’re properly addressed by name.
So not fixed names for your empire after all... what a load of crap.