My father grew up in a neighboring town to Liqian, in Gansu. This is essentially an urban myth of sorts that several locals still believe, though as the article itself points out, it's been proven false a decade ago. In recent years they've constructed several faux monuments and landmarks in a cheesy emulation of Classical architecture in order to attract tourists.

People want to believe it; it's an interesting theory. However, the genetic diversity in this region comes primarily from Yugurs (a Turkic group related to the Uyghurs which converted to Tibetan Buddhism around a thousand years ago) and Mongolians.