This is going to be big business I think. I have probably sent hundreds of thousands of emails, texts, chats, etc. It would be well within the realm of possibility to train an LLM on a loved ones communications corpus and allow you to chat with "them" after they're gone.
Possible? Yes. Convincing results? Probably. Good idea? I doubt it.
Possible? Yes. Convincing results? Probably. Good idea? I doubt it.