Nope, no work except for their installation of the 21" Arachnids (not powder-coated or otherwise modified).
p.s. Not a materials scientist of physics professor, but as for the powder-coating as a reason for warped rotors . . . a novel theory but I've never read or seen any evidence to suggest the wheel is much of heat sink for brake energy.
Then I would say you have a strong case and that’s pathetic that Tesla is denying it. I have my doubts about powder coating being a cause as there are others like yourself that have had this problem without powder coating or other modifications. Good luck on challenging it, Tesla should do the right thing.