While this is vague and open to some interpretation, one possibility is that the paper was not accepted by the journal and this self publication is a way around that problem.
To be fair, this is completely irrelevant to whether the genus & species name is valid. The PhyloCode will require that all valid nomenclatorial acts must be peer-reviewed -- the ICZN doesn't mention peer review at all.
(And of course we can all digress into horror stories about peer review. I know a manuscript that was submitted to Nature and rejected based on three incredibly incompetent reviews. The authors are now reformatting it for Science... it really would have deserved to be published 1) in Nature and 2) as quickly as possible.)