It might nutty as you say, but it’s not new. The NYRB article is paywalled, and I am unable to read it. It may well be that the origin of the concept was elaborated in the article, but I just want to point out that it was popular among 19th century Russian geopolitical thinkers. Following the dissolution of the Soviet Union, the doctrine was resurrected as an alternative to communism and a justification for a neo-czarist, expansionist foreign policy. Brzezinski discusses the phenomenon in The Grand Chessboard (1997).

All of a sudden, you had people who had for decades during the Cold War decried geopolitics as a tool of capitalist militarists now calling for the reclamation of the Russian Near Abroad and referring to the Heartland as if Mackinder were now their thought leader on geostrategy. The case was made that a truly reformed Russia would be in a better position to wield influence and soft power throughout its Eurasian periphery. Again, it might be nutty (Russian messianism is nutty), but there is Solzhenitsyn in 1991 suggesting that “...the time has come for an uncompromising choice between an empire of which we ourselves are the primary victims, and the spiritual and physical salvation of our own people”. The Russian Idea.

Of course, none of this means that Georgians, Armenians, or Uzbeks will begin to think of themselves as “Eurasians”. Eurasia might be a useful concept for geographers and geo-strategists, but Ukrainians, Kazakhs, and all the others pine to be Europeans.