Statehood is not irrevocable.
The rebel states lost their soverignity when they committed insurrection. They got back in only with permission of the other states.
If PR wants to leave the US they can- with the permission of the other states. If that permission is not granted, then no they can not. Such permission could be expressed by
Successful Supreme Court Case.
It was never adjudicated, no matter how many times you post that drivel.