I am interested too on this Facebook Libra coin. But of course, I will wait until it is already available. This is just a strong proof that more and more people or groups accepted cryptocurrency.
It is not a threat to BTC or other altcoins instead a helping factor for the awareness of people around the world because social media specifically facebook have millions of followers and users. Facebook Cryptocurrency will be another breakthrough in the history of Crypto.
I would invest into Facebook's cryptocurrency too, as I believe that it will gather lots of attention within the mainstream world at launch. But as a real currency for daily payments, I wouldn't recommend using it since Facebook is well-known to invade people's privacy. Libra will never become a threat to already established cryptocurrencies like Bitcoin and Ethereum since it's completely centralized. Facebook's cryptocurrency will look more like another central bank, than real a crypto with a permission-less Blockchain.
Which is why, it's no secret that Libra will behave the same way as Ripple's XRP. By sacrificing decentralization and censorship-resistance, Libra will be able to obtain massive transactions per second (TPS) and very low fees. Because of these "benefits", people might tend to use Libra more than Bitcoin or any other altcoin within the mainstream world. Despite this, the future of Libra is uncertain, as regulators are questioning its legitimacy.
Which is why, Libra could either fail altogether or become successful enough to drive Blockchain technology towards massive adoption within the mainstream world. Just my opinion
