For TTS, the "tone" is something you should encode in the input rather than have TTS figure out. I can imagine ebook > LLM > annotated text with speakers, emotions etc > TTS. So the TTS can remain rather dumb.
For the self-driving car, it shouldn't know cultural norms and be "more careful" sometimes. It should always know how much it sees and what stoping distance it can get with max breaking and its reaction time and adjust accordingly.
Agreed on stuff like emergencies etc.