I don t see anywhere in that blurb where it s keeping them out As for magnitude they specifically use that for naming purposes and for the purpose of naming That s purely bureaucratic to decide which governing body gets to decide on a name It is independent of the astronomical definition of a DP Plutoid which in that same blurb is said to be celestial bodies in orbit around the Sun at a semimajor axis greater than that of Neptune that have sufficient mass for their self gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium near spherical shape and that have not cleared the neighbourhood around their orbit That definition has not changed Sedna Quaoar Orcus and OR10 are Plutoids DPs per this definition but they fall under CSBN purview for naming We can certainly note that the names for these objects were approved by the CSBN rather than the WGPSN if anyone cares but that has nothing to do with their physical nature