Between 11 and 4 kya, AP were in turn largely replaced by another group of peoples with ancestry from East Asia, the "Neosiberians" from which many contemporary Siberians derive.
The paper describes a "major population turnover in northeastern Siberia, with Neosiberians arriving from the south largely replacing AP", but where in the south did these Neosiberians originate from? There may be a clue in your more recent posts about studies of Jomon aDNA.
The earliest known pottery in the world was found in south China. From 14,000 years ago cord-marked pottery became widespread from Thailand to Siberia (the lower Amur basin and Transbaikalia). The Jomon aDNA studies show that the Jomon people, who also had early cord-marked pottery, had genetic affinities with coastal east Asian populations from Taiwan to Siberia. I suggest a south to north coastal migration of pre-neolithic pottery making people from southern China to northeastern Siberia between 14,000 and 11,000 years ago, with substantial population replacement along the way. I look forward to further aDNA studies producing evidence that addresses this hypothesis.