[soveran]

I don't think the paper assumes a many worlds interpretation.

[platz]

that's what it claims, but that is the only way to make sense of "particles are epiphenomena" + "Thus the Schroedinger field is a space-filling physical field whose value at any spatial point is the probability amplitude for an interaction to occur at that point."

it is saying that the only thing that exists is the quantum wave function

the only theory with a hope of credibility/coherence that says the only thing that exists is the quantum wave function is many worlds.