NAT64 is a subset of a different thing that existed since 2000 though, when v6 was ~5 years old and before most OSs even had support for it.
I don't believe this ever worked at scale, even if it is pretty much NAT64. Particularly the part where IPv4 hosts can reach IPv6 systems with the NAT-PT tracking through DNS what is given out in A records is "a bit much".