But good lord, sometimes trying to get technical help on the Internet turns into this rabbithole of people who are specifically looking for ways not to be helpful. "Did you really want that?" "Did you consider alternatives?" "What you really have is an XY problem."
"Truly identifying a problem means looking deeper at the symptoms, the customer, the impact, the alternatives, the opportunity, and the relationships between them, while avoiding the “solution bias” (often known as “The issue is that the customer does not use my solution”)."
Or not. Not everything has to be this super-deep, six whys exploration of how craving and attachment is the cause of all suffering and if you would only stop wanting a solution you would no longer be in pain.
"I'd like to prepare, just in case, to have technology to reproduce her voice from keyboard or other input."
He then goes on to say "My ideal would be an open source 'deepfake toolkit' that allows me to provide pre-recorded samples of her speech and then TTS in her voice."
That sounds like wanting to capture and simulate someone's voice.
People are being downvoted because if you cannot possibly have an informed opinion on a subject, it's completely arrogant to form opinions on that subject, and even more arrogant to criticize someone publicly based on those opinions.
Literally the only person on this thread who knows anything about the OP's wife is the OP. Everyone else sharing an opinion on "the emotional side of this" is vocally ignorant.
She can, but she might not. A lot of that depends on how he presents the idea to her -- it might seem like something that's important to him.