Combine that with AI to emulate their voice, and AI renderings to use photos of their face to render a 3d model that moves it's lips and face realistically as it talks (both of which already exist). Yeah, you could with today's technology "bring back" a loved one and be able to talk to them, even verbally, and see and hear them respond and even have some shared history in common, if it was in the training set.

It could send you greetings automatically on your brithday.

Would it be helpful in coping with loss, or just a painful reminder? I don't know. Maybe both at the same time.