It seems like the FB founder has nothing but positive things to say about blockchain technology.
There are rumours going around that he will release a cryptocurrency for use on WhatsApp, but given the privacy and censorship concerns over FB, I can't see many people going for it.
I guess in the meantime he is just contributing to the development of the block chain, this might lead to a better adoption of some facebook users if it continues to do so, well, cryptos will increase further.