GVWR over 10k on new truck, need commercial plates?

I don't see anything here about vehicles over a certain weight requiring commercial tags.

When I bought the 3500 the dealer told me it was going to get commercial tags because the curb weight was over 6000 lbs, period, end of story, nothing could be done. When the plates showed up in the mail they were passenger plates and the curb weight on the reg was 5650.