There is no evidence that the Urumqi mummies spoke Celtic languages, or that they were Europeans, or even Indo-Europeans. The DNA evidence can only be used to show that they were of West Eurasian, not European origin. As for their language, none of them have been accompanied, as far as I know, by any writings. It is reasonable that they might have spoken an Indo-European language, although by no means proven.One of the many idiotic statements in the article:
It is a sad state of affairs that editors allow such misleading information to be published.
The Loulan Beauty, for example, was claimed by the Uighurs as their symbol in song and image, although genetic testing now shows that she was in fact European.The "Loulan Beauty" may be one of the ancestors of the Uighurs, and she certainly belongs to the archaeological heritage of the region. Thus, it is reasonable and understandable that she will be made a symbol by the current inhabitants, however tenuous the connection.
Even the Slavs of Bulgaria identify with the ancient Thracians, the Turks identify with the Hittites and other extinct Anatolians, the Arabs of Egypt identify with the Egyptians, and the modern Germanic-speaking Britons identify with the "Celts". Such sentiments are understandable, albeit naive.
What is not excusable is to excise a part of Central Asian history and claim that it belongs to Europeans, or even more absurdly to Celts. However, we should perhaps excuse the journalist for his misstep, since he lives in a country where even professional geneticists have consistently oversold their research to a credulous public ready to swallow up stories about "Viking", "Celtic", or "Pictish" origins.