Murph won't be back because Mab, Harry, Molly, Lara, Thomas remember her. All long living people. And even if some of them fall soon, not all of them will. Also, Gard herself remembers her.
Of course, we could see a ghost (thanks to Morty? Liberty?) and I agree about her appearing in MM.
I actually dislike this afterlife for Murph, as she was a catholic. Her place is in Heaven, with her family.
On topic: I don't think Rudolph will go to jail. He may end in a psychiatric but I suspect he is still a threat. But I hope Kinkaid ends him with extreme prejudice.