There is a lot to think about here. One question I have is about this quote:
" We found that this puts a limit of about 500 thousand years on a bottleneck. More ancient than this, there does not appear to be strong evidence against a bottleneck. That means, if “human” is either of these two definitions, perhaps Adam and Eve could be the sole-genetic progenitors of all of us: (1) The Homo genus (2 mya), or (2) Common Ancestors of Homo sapiens , Neanderthals, and Denisovans (500 to 700 kya)."
Language is so ambiguous sometimes, and its a difficult subject. No wonder we have lawyers. It seems to me that the door would still be open to a single couple 500K ago that was Homo Sapiens that was the “sole-genetic progenitors of all of us”. This couple would appear after Neanderthals and Denisovans (let’s say they came along 600,000 years ago). And despite the introgression of Neanderthal and Denisovan genes into some of us this single couple would be the only ones who could claim to be the genetic progenitor of all of us.
That is to say, many sub-Saharan Africans have no trace of Neaderthal genes. Until 55K ago, basically 90% of the existence of Homo Sapiens, it seems likely that most of us had no trace of such genes. There was a mysterious Eurasian group coined the “basal Eurasians” who seemed to lack it as well, until they mixed with Iranians, Natufians, and Anatolians and produced the world’s first farmers less than 15K ago.
I think I see what you are trying to say, but do the words you use actually say it? It is hard to justify, IMHO, calling a hominid which makes a non-universal genetic contribution to our species after 85% of our history has gone by since the original founding couple a “progenitor”. Maybe “Sole-genetic progenitor/later genetic contributors” is a more accurate way to put this?