The letter is strange. I could be misunderstanding something but it seems that NHTSA is saying that the right to repair law is unsafe because "the open remote access to vehicle telematics effectively required by this law specifically entails the ability to send commands."

But this functionality already exists, no? In fact towards the end of the letter they also discourage automakers from disabling telematics to comply with the Massachusetts law because "telematics data can also be an important source of information for safety oversight and field performance monitoring by the authorities and vehicle manufacturers."

I'm mostly just glad I drive an older car which barely gets an FM signal.

Full letter: https://media.wbur.org/wp/2023/06/06-14_NHTSA_Telematic_Lett...