[mapt]

It doesn't seem like an outlandish possibility.

That's distinct from making a claim, an assertion with supporting evidence.

To make a claim, we would want evidence, and the evidence here would be a genetic isolation (lack of chronological overlap, synonymous with lack of interbreeding) of ancient Asian humans from ancient African humans. This requires sequencing a lot of ancient Asian DNA, which seems not to have happened yet. We barely have a cohesive evidence supported grasp of Neanderthal interactions in Europe, but are gradually updating to support more and more absorption by interbreeding.