I refuse to believe that the actual measurements are inaccurate to a notorious extent as it is not rocket science to operate a caliper. I am way more inclined to believe that the discs sent to reapproval, or the discs you measure at home, are indeed very different from the discs sent to PDGA. It is not that uncommon to find visibly different discs within the same run, let alone across different runs.
I'm not entirely sure if your comment implied (unjustly) PDGA's incompetence in measuring things or if you referred to run-to-run variation in disc dimensions but if it was the latter, then feel free to ignore this reply