The prerecorded message seems sufficient for that use case. If I had a relative in that situation, I'd want her to be able to talk to a human - it might be an actual emergency or problem, but even if not...

Right. My brother and I discussed this out of curiosity and you're spot on. Prerecorded message is sufficient, and AI introduces too many wildcards.

But the biggest reason is that ethically, it somehow seems very wrong to trick my grandma that way.

Not sure why parent comment is getting downvoted though, it's certainly an interesting idea.

As my brother said, this is a really tricky area for us to explore for non-technical reasons. We go back and fourth on this, as I do believe my grandmother's quality of life would improve dramatically if this could be done well. For now, we've decided not to explore this, but I think it makes more sense to build personalized AI assistants for people who do not yet have dementia but who are concerned they may in the future