The interview in the magazine itself is quite interesting, with some stunning photos. He has however talked about drugs, tattoos and scarification before so it's nothing new - the article in the main newspaper is cobbling together out-of-context quotes and speculation for the sake of sensationalism.
Most likely explanation at the moment is that Polunin and Zelensky made a joint decision to withdraw when they realised the production was a turkey, and Sergei has gone to ground to hide from the intrusive press attention. Fingers crossed he's fine and will keep his upcoming performance commitments at the Stanislavsky.