Network Prefix Translation isn’t the same thing. That’s used for things like MultiWAN so that your IPv6 subnet from another WAN during a failover event can still communicate by chopping off the first half and replacing the subnet with the one from the secondary WAN. It is not NAT like in IPv4 and doesn’t have all of the pitfalls and gotchas. You still have direct communications without the need for things like port forwarding or 1:1 NAT translations.
I’m a Network Engineer of over a decade and a half. I live and breath this shit. Lol.
Just because you can doesn’t mean anyone does. I’ve never seen an ISP hand out “private” IPv6 addresses. Ever.
If you’re doing NAT on IPv6, you’re doing it wrong and stupid. Plain and simple.