It's not a cryptocurrency though. It even says in their white paper that it's a permissioned system. Calling it a cryptocurrency is just marketing to ride on the hype train.
Obviously the point is to ride on the hype train by redefining the original meaning. It's similar to a "democracy with a dictator", it just doesn't make sense.
Yes, and Facebook hasn't lied to us before? They don't have an actual plan on how to accomplish this transition, which necessarily includes completely redefining the whole system Libra is based on.
It is not a good idea to take what Facebook says at face value. It is worth examining anything they say in an extra critical and sceptical way because of their (at this point) well-documented willingness to lie and bend the truth.
The whitepaper also says that Libra will launch permissioned and transition to a permissionless cryptocurrency.