Banks with no doubt will shill Libra with their most effective and expensive marketing. That's how I only see it.
Legacy banks want no part of it. Libra only threatens their market share for international remittances, as customers will move away from bank wires and towards the cheaper payments offered by Libra. Companies like Stripe and PayPal might be along for the ride, but legacy banks will probably be pushing their own competing products.
Included in the List of companies supporting Libra, are VISA & MASTERCARD
...which are not banks. Visa, Mastercard and similar payment processors will be happy to implement Libra into their POS products and take a cut from merchants like they do today.
Banks, on the other hand, only stand to lose if people start holding funds in Libra/Calibra instead of bank accounts because it's cheaper to remit internationally. Just like banks created Zelle to compete with Venmo, they'll create a new, cheaper and faster system to replace SWIFT and begin competing with products like Libra.