If it ever does get there, (which I very much doubt), the mechanisms will be so complex as to render them to be undisputed evidence of intelligently guided design. And whatever does comprise the "self" will still be offered new life in heaven.
Complexity is not evidence, and certainly not 'undisputed evidence' of an intelligently guided design(or designer). Evolution, which can result in huge complexity, does not require an intelligent designer. Your statement that the 'self' will still be offered new life in heaven is pure assertion, as you have not given reasons which establish any 'self', nor its quality of surviving mortality, nor the existence of any sort of 'heaven.'
I tried to answer your thought experiment as straightforwardly as I could, but unfortunately you haven't seen fit to answer mine in a similar vein, because you have simply replaced 'soul' with 'self', completely disregarding the point of my thought scenario, which suggests clearly that a soul is excluded. I find that disappointing.