I don't think there has been anything much "leaked" at all. To the contrary, the Mariinksy press office gave the information that she was leaving soon. Stepanova does not run that Facebook page, and on her Instagram, she is nothing but gracious.
I agree, all these fans urging each other to pester Mariinsky etc. is very annoying, but in general the story around her is simply "Why isn't she getting better parts? What a disgrace!" Hardly confidential.