Facebook can have an internal payment system that uses local currencies. There is no reason it needs to create its own currency, except as a power grab. Building out a Paypal clone is fine enough.
How can it be a power grab, Libra was going to be at least an open system with it's own wallet protocols and market for implementations. A WeChat style system would be totally closed from the ground up.
No, it was going to be open to partners that Facebook picks and chooses. It was very specifically not to be a fully decentralised blockchain, which essentially means it's actually a big permissioned database, which the database owners get to control.
