> IPv6 without a NAT exposes information about different devices inside the private network.
In practice this has not been true for over 20 years.
IPv6 devices on SLAAC networks (which is to say, almost all of them) regularly rotate their IPv6 address. The protocol also explicitly encourages (actually, requires) hosts to have more than one IPv6 address active at any given time.
You are also making a wrong assumption that the externally visible address and port ranges chosen by the NAT device do not make the identity of internal devices easily guessable.
In practice this has not been true for over 20 years.
IPv6 devices on SLAAC networks (which is to say, almost all of them) regularly rotate their IPv6 address. The protocol also explicitly encourages (actually, requires) hosts to have more than one IPv6 address active at any given time.
You are also making a wrong assumption that the externally visible address and port ranges chosen by the NAT device do not make the identity of internal devices easily guessable.