Every neuron in the layer encodes fractionally something about the concepts embedded in the whole thing. It's more like a hologram than a series of connected facts.
If neurons do 'one thing' then their position encodes the relationships then snipping out that one weight would make the net forget that one thing. And we already know from many practical experiments that this is not the case. So I really wonder what the underlying mechanism is for that claim to be true.
Re the first paragraph I'm not sure what you mean by "the assumption that conflates multiple concepts that to me are substantially non-overlapping are one and the same thing"
There are lots of examples of things that we can describe to a very high degree (life itself, for instance!) but that we do not necessarily have the ability to explain.
Personally from reading the article, I felt like it scratched the 'why' itch more than the 'what' itch which presumably is what you mean by explanation vs description but it is fairly dense and I can see how either interpretation would work.