I think you are missing the point that using LLMs to improve Alexa would certainly be hard, but it would have been massively worthwhile if it worked. Microsoft and Google are well aware that LLMs have the potential to upend the search dominance of Google.

I am also much less concerned about jailbroken LLMs, because Alexa is already so broken it can't get much worse. Normal users don't seem to care much about potential misuses (compare with search autocomplete biases of Google) as long as a service works for them. But unless you widely deploy a tool, you won't uncover how it is abused (see Sidney's launch).