I looked just about every place names (or namelessness) are mentioned in the Tao, and here’s what I’ve found:
Basic creation myth: The unnamed gives birth to Name, and Name gives birth to Nature (“the ten thousand things”) The deepest, most eternal truth is the unnamed.
The Way is also talked about as nameless or inexplicable. In that sense it is the ultimate beginning – and since Taoism is about returning to the beginning, the ultimate ideal. Naming – although necessary for human society - is dangerous when taken to the extreme. There shouldn’t be so many names that people no longer can no longer see the whole, the big picture.
Another thing – real names can’t be spoken. (“The name you can say isn’t the real name.”) Often Lao Tzu will tell the reader to “call” the Way great, intangible, unformed, etc., but that isn’t its real name. In a sense real names transcend language. I’m not sure if this is the same thing as namelessness, but it’s still a bit problematic for LeGuin. In the Earthsea novels, her characters talk about the “true names” of things which can only be said in a certain language. If names can’t be spoken, then whatever words Ged or Ogion use aren’t really true names.
