I don't have access to the paper, but it seems to make zero testable predictions and is therefore just mathematical fiction. If it's not falsifiable, it's not science.<p>EDIT: the last sentence is "Given sufficient redshift (or, equivalently, time) resolution effected by the redshift slicing, one might just find that the Hubble diagram exhibits jumps in the redshift distance relation, which would be very revealing."
So they say it's testable. However, we see the effects of "dark matter" (or whatever it really is) today affecting the spin of galaxies, so I don't see how that's compatible with the explanation of these events being "rare".