The ancient people of Lagoa Santa were Native Americans — this is established by the genomic evidence and is not in question.

What has changed is the understanding of the internal structure of the founding population, the specific genetic diversity that that population carried, and the ways in which that diversity was distributed across the Americas as the initial settlement proceeded.

This is a finer-grained picture than was available before, and it is more accurate as a result — not despite the complexity but because of it.

The Population Y debate is not a crisis for the understanding of the first Americans.