Rereading this, I should have added more context. Wikileaks can only publish what it's given, and there's no reason to suspect they receive much about Russia.
Imagine you're a Russian and you have information about the government that you want to leak. Would you give it to a primarily English speaking organization, with no Russian speakers on staff, that nobody in your community has ever heard of and has been alleged to have ties to Russian intelligence for years?
Or would you give it to a Russian speaking organization that has connections in Russia that could potentially help you if things get bad?