I've heard that "fired dirt" analogy before.
I think that firing the clay component to any temperature sufficiently high that the substrate doesn't fall apart way too fast, would also be sufficient to break down most organic components. Sure, the nutrients are still there, nothing short of nuclear processes destroys elements. But in the end, I doubt AS can truly be classified as organic.
its loaded with hemic acid, aka humus,
that is its main buffering compound