That appears to show that it can't answer some obscure trivia question to the standards of the blog post author. Nothing to do with generalizing concepts.
It immediately cuts to the heart of the matter - an LLM does not understand things. It does not know anything but which word follows another. It can't do anything but regurgitate things it has read in an incredibly lossy manner.
But it's a neat party trick that seems to fool a lot of people into thinking that there's something legitimately useful, here.