Nah, I don't think there's a lot on IPv6 in that book. I think OP's concern is valid. Accessing devices at home isn't unheard of. The amount of smart home stuff, appliances and consumer products increases every day. And we all gladly pay our ISPs to connect us and our devices to the internet. They could as well do a good job while at it. I mean should it cost extra to manage a static prefix, so be it. But oftentimes they really make it hard to even give them money and get that "additional" service.