As far as I know, it's not confirmed. (Yet, not sure...)
My latest here: https://medium.com/@olesia-filipenko/why-great-russian-literature-is-fake-f04630fe61c4
Written by Olesia F.
Content writer from Ukraine; in love with books, cats, and jazz. My publication: https://medium.com/writing-breeze (check "About" if want to support.) Thanks!