Do they have the capacity and the gall to try that with bitcoin?? Definitely no.
I think they will try. Zuckerberg's greed seems to know no bounds.
Nobody to stop him in the name of net neutralityn once they use those "billion dollars for development" to prop up their shitcoin on a few exchanges.
I don't think it will be tradeable on exchanges, because I don't think it will be a cryptocurrency at all. Zuckerberg and Facebook are all about control and invasion of privacy. They want to know everything about you, all your communications, your browsing habits, your pictures, your location, the lot. I can't see them giving up control of their own currency to a decentralized network. If it is even blockchain based, it will be just like EOS - entirely controlled by a small number of "high up" users, with the ability to reverse transactions and seize coins at will. They will relish the opportunity to start collecting data about your spending and banking habits too.