Just glanced through it and did not see the question of the speed of other massless particles (e.g. possibly neutrinos) adressed. They talk about an infinite bare velocity and that the finite speed of photons is due to multiple interactions. If that were the case, other particles that are less interacting than photons would go faster. I did not see this adressed anywhere in that paper (which, admittedly, I read rather quickly.)
So, they're saying that light's speed of propagation is a function of the properties of the medium in which it propagates. In other words, michelson-morley experiment is bunk, no?