The appearance of the Turkic language is very recent but the genetic signature of them is more ancient and goes far into early Iron Age. Simply because allot of the Western Turkic groups are basically turkified Iranic tribes.
Take a note, the article even states the Eastern Scythians were most similar to Kipchaks. Kipchaks are amnong the most West Eurasian like groups among Turkic speakers infact since decades scientist argue that Kipchaks are basically turkified Scythians.
Also interesting how the study points out most genetic similarity to Central Asians and Caucasians for West Scythians which again proves my point that when most Indo_Iranian tribes emerged they were already heavily mixed with more CHG/Iran_Neo like groups from cultures like the BMAC. In fact the origin of the Scythians seems to be the southern parts of the Andronovo culture close to Yaz culture. Thats also where Greek sources point to where Scythians came from. It's pity that they have no Anatolian_Neo sample to compare with. Some of "WHG" in Iron AGE Adygei and Russia is most likely Anatolian_Neo derived.
Also the study pretty much confirmed by we all should know. Scythians were basically West Eurasian with some East Eurasian admixture towards the East. And they appear like one uniform group debunking allot of biased theories about their origin being mixed or them being some kind of multi-culti group mixed of Iranics, Uralics, Turkics, Slavs. The opposite is the case they have been absorbed by some Turkics, Uralics, and Slavs but their origin is clear visibly Iranic.