From my side I like how it's handled :

• From one side the blockchain will be run by the non profit swizz association Libra, and facebook will have only one of the many vote on the gouvernance of it, as the other members :
  "A note on Facebook, Inc.’s role — Facebook teams played a key role in the creation of the Libra Association and the Libra Blockchain, working with the other Founding Members. While final decision-making authority rests with the association, Facebook is expected to maintain a leadership role through 2019. Facebook created Calibra, a regulated subsidiary, to ensure appropriate separation between social and financial data and to build and operate services on its behalf on top of the Libra network. Once the Libra network launches, Facebook, and its affiliates, will have the same commitments, privileges, and financial obligations as any other Founding Member. As one member among many, Facebook’s role in governance of the association will be equal to that of its peers."
• Then concerning Calibra : Facebook Libra's wallet which will be integrated through what's app and messenger, this should be totally decoupled from facebook inc, no not mixed up with social data.

For me it's looks like a serious alternative to banking systems and actual crypto as each has it's own drawbacks.