I guess you are right. DNG converter is generating a new file from a locked file so the new file doesn't have to be locked.
I can live with that logic now that I understand why the change in my workflow caused PM to quit showing camera locked images as tagged.
Do all locked images show up as tagged in PM? Or does Tagging an image with PM lock that image?
I know that my problem has nothing to do with PM. It just seems that the DNG Processor should recognize that the nef was "locked" in camera (which is really the shooter Tagging it or saying, "Hey, this is a good one, Treat it special" and save that setting somewhere.