That can be done with randomized assignment of addresses to hosts rather than dynamic address translation. Everyday you come to work you get a different addres

That can be done with randomized assignment of addresses to hosts rather than dynamic address translation. Everyday you come to work you get a different address. No need to do that dynamically at the network border or on a per connection basis. But thank you for pointing out explicitly one of the 'reasons' that is given for IPv6 NAT.