The genetic work actually does include those people, namely those whose descendents have been sampled.

So any population wiped out by genocide, famine, or plague is unsampled. The Amazon basin hosted many millions of people for millennia until smallpox, diphtheria, and measles were delivered to them.

No? Even genocides leave descendants. Moreover, who was doing this hypothetical genocide that didn't have kids?

As I said before, it's not logically impossible that a highly populous society existed in the pleistocene. But the constraints it would have to fit grow increasingly contorted as the state of knowledge improves. At some point it starts to resemble a small colony of advanced alien settlers who landed one day and disappeared a short while later. That explanation might honestly be easier to account for than what some people propose, since they don't have to develop their tech from scratch here on Earth.

How strong a signal do you get from the Chatham Islanders, wiped out literally weeks after the Cook expedition told the Maoris about them?

1) the moriori still have living descendents today and

2) it's pretty clear from both this comment and the substantial edits above that this discussion isn't in good faith

Ignoring the gaslighting, how much do we know about the Chatham Islanders' pre-contact culture? And, how many of those descendants have non-Maori Y chromosomes? Any?