Like you mentioned, videos and photos are static memories. I do think that back in the day, when people did not have such static memories to cling onto, it probably helped them mourn and move on much better. In our day and age, the static memories themselves trigger emotions that messes us up and slows our ability to move on.
But this AI is a whole new level beyond static memories. I believe that our minds are quite dumb and that this kind of AI can really trick us into not accepting the loss. I do feel it will extend our state of denial, kind of like how Mal felt in the movie Inception.
But I can also see how this can be helpful in few cases. For example, it would be great to have a lifetime almost-real bot of Stephen Hawking or Kalam Sir or probably even Jayalalitha (so that Panneerselvam can take her blessing and guidance for every decision).