Secondly, you should reread their post, it’s much broader than your interpretation. They were envisioning a world where the device and copying restrictions we have today don’t exist.
My reference to quantum was saying that this usage pattern would require something like quantum entanglement to replicate the state of which copy is active among all copies.
They can't, which is the same as it is now. DRM is a farce and everything is on The Pirate Bay. Which is why restricting libraries like this is ridiculous -- anybody who doesn't care to follow the law doesn't need to get a copy from a library, they can just download it from a piracy site. The reason you go to the library instead is that you want to follow the law.
That's how it works in every library system I have dealt with