The problem I see with this is that you are using a powerful, sophisticated technology to trick your brain into believing a lie, the lie that you are talking to your dead loved ones rather than to a bunch of chatbots made to superficially sound a bit like them based on a few questions, recordings and the like. This can only end in two ways: either you permanently erase the distinction between truth and lies and lose your mind, or you come back to reality with fresh grief and disappointment after each conversation.

Some point out that people often cling to old pictures, letters, personal belongings and video recordings, and these chatbots can be seen as an extension of that practice. Well, for starters, that should be done in moderation too, but more to the point, those things don't mess with your mind nearly as much because they don't try to simulate a fresh interaction.