NHTSA crash test ratings are within the car's class only. A 5 star subcompact may well be less safe than a 4 star minivan. The model S is likely (my opinion) more safe than a model 3.
I believe the Tesla marketing would have been more true if it had included "... in an NHTSA-style incident" or some such. But that's not how marketing works.
It is not obvious that you have followed kalleboo's advice, in the post you are responding to, and read the NHTSA's letter.
Star ratings are only valid to compare within their weight class.
They should make a new rating then, to convince all Americans to drive 16 wheelers :)
I think we've just figured out how to get Americans to ride more trains!
Ehhm, maybe to drive trains. One engine, one person. That might work. And their own tracks.