" 
 :::::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. —   "