Cinavia is currently mandatory for blu-ray players only, NMT manufacturers would be shooting themselves in the foot if they implement any sort of DRM in their products, given that the vast majority of their users utilize DRM-free downloaded media
no issues with genuine BDs played on BD players.
no issues with unauthorized copies played on NMTs.
if a cinavia protected movie is played on a BD player also capable of reading downloaded media, content protection will engage.