If you look at the Summary of Constituency Statements on Future new Services or Actions by gTLD Registries on the GNSO web site, you'll notice that the gTLD registry constituency -- presumably the constituency most directly impacted by the ongoing PDP -- is the only GNSO constituency that has not submitted a constituency statement in this process. From a statement on this process submitted to the GNSO by Neulevel, we now learn that the reason for the gTLD registry constituency's silence is lack of consensus.
Neulevel's submission includes a detailed description of a possible review process. Although I haven't digested the details of this proposal, yet, I'd recommend a look -- as far as I know, this is the first time that one of the gTLD registries speaks on the record about detailed ideas for a "registry services process."