Most ISP I have seen implement it like this. A large chunk of those "most" also require you to bind a phone number to each separate hwaddr appearing in the network via SMS. (Not all though.)

Those few that implement it differently, do the following:

They serve ULAs to the customers over slaac, and nat6 all the ULAs to a single ipv6 assigned to the router (actually a wifi hotspot).

I totally believe that where you live things are done differently, but this is exactly why ipv6 critics call it defective. It allows too large a variety in implementations.