Source? For any of this? But specifically the bolded. What evidence do you have that this will be the ultimate expansion dealing with this theme?
Also, as @Ielenia has said multiple times. This expansion is not about Death, it's about the Afterlife. Those are not the same thing., similar and related, yes, but not the same.
As I said before, your entire premise is based on an assumption that is not supported by any evidence right now. This is your head canon.