My understanding is that the proposal here isn't that an accurate simulation of your life should be counted as an afterlife; it's that a somewhat-accurate simulation of lots of bits of your life might be a necessary preliminary to providing you with an afterlife (because they'd be needed to figure out what your brain, or at least your mind, was like in order to recreate it in whatever blissful -- or for that matter torturous -- afterlife might be provided for you).

As for Newcomb versus prisoners' dilemma, see my comments elsewhere in the thread: I am not proposing that our decision whether to engage in large-scale ancestor simulation has any power to affect our past, only that it may provide some evidence bearing on what's likely to have been in our past.