Abstract of the original Nature article - https://www.nature.com/articles/nature25173 - full text needs payment.
The NY Times article is probably the best version - https://www.nytimes.com/2018/01/03/science/native-americans-beringia-siberia.html
https://www.theguardian.com/science/2018/jan/03/ancient-dna-reveals-previously-unknown-group-of-native-americans-ancient-beringians
http://www.bbc.co.uk/news/science-environment-42555577
Interesting, thanks 8)
From some brief Googling it appears to be distinctly unclear if they bearers of the Denali complex lithic culture died out or simply adopted new tool traditions.
Reading the Nature abstract, it says "Our findings further suggest that the far-northern North American presence of northern Native Americans is from a back migration that replaced or absorbed the initial founding population of Ancient Beringians." So unlike the impression I got from the NYT piece, it seems far from clear that the "Ancient Beringians" disappeared - it may be their genes simply got swamped by back migrants from the "northern" group, but their lineal descendants are alive and well today.