Anything is poissble, plus the way the crypto world is going. Mark might see it will only profit him even more and so decided to take a part in it
It could be possible to some extent but it will be hard too, because creating own crypto currency is not so easy it takes years to promote it and to develop it, people never trust anything new that easily so making them trust your currency, then finding people to invest and buy so I think it is not possible to happen for more than 5 6 years, so we are happy with our bitcoin and will use only bitcoin.