Notice buffet hasn't told anybody what to do with their money in 2016...
Maybe he is secretly investing into bitcoin. But this might be against his advice. He does not see cash flow from bitcoin.
i don't think he is investing in bitcoin in secret. especially when it's done through his berkshire hathaway. every investment, no matter the size, must be made publicly for the share holders. if he really had invested in bitcoin or a bitcoin related startup, then we would have heard about it already.