That's a great theory! I haven't heard of that one yet.
It's from Discworld if I remember correctly.
Except they always saw Death as a skeleton because he didn't want to bother with all the shape-shifting because while he gets the job done, he's a bit lazy with the unnecessary bits.
Also I would assume that eventually either nothing because the apocalypse prevents the following, or someone finds a way scans everyone's brains right before they die, past and present, and recreate them either in virtual reality or normal reality (depending on overcrowding of real reality) and therefore, since your brain is exactly the same as the moment before you died, you perceive no passage of time when there must be loads of time. I mean, if we were to start doing this NOW, there'd be a lot of historic and prehistoric people to save. Restore someone from B. C.? Over 2000 years ago, but to them it goes from that year to 2016 in no time at all.