Is this in anyway an authoritative source? The CIA, if you believe everything, is responsible for meteors, volcanos, climate change, AIDS, population growth, population decline,.... or is it maybe just rubbish?
Hardly. 'Slipped Disc' is primarily pile of factless gossip and twaddle, with specific and persistent interests in publishing lies about Valery Gergiev, Anna Netrebko, and other Russian performers. The author of the 'Slipped Disc' website has lost several legal battles, in cases where he printed complete lies about record labels - and was forced to pay punitive damages. The man is a complete charlatan, with no knowledge of classical music whatsoever.
Relata refero
https://www.thefreelibrary.com/Checking+the+post%3A+music%2C+postmodernism+or+post-postmodernism.-a0197666625P.S.
Gergiev made a lot of enemies,read forumklassika.ru