That is a trivial fact, the wave function of a system completely describes the state of the system and that of course includes the angular momentum. But the wave function has nothing to do with a physical wave with physical properties, it is a pretty abstract construction and the physical properties are essentially encoded in the base vectors of the Hilbert space. I only skimmed the paper but I didn&#x27;t come across something that plausibly argued that the wave function is the fundamental physical entity.