alt Hacker NewsNAT is not inherently a security feature, however where NAT happens is somewhat important.
A local router that I can control deals with how to map from my public IP to my private IPs.
This is not security but is obfuscation of the traffic.
Obfuscation becomes almost impossible in the IPV6 context where NAT isn't necessary, it becomes optional, and given the likely trajectory that option will be exercised by sophisticated enterprise customers only.
As the article mentions, if you want to use NAT with IPv6, you can. The fact that it's optional doesn't mean that address obfuscation is suddenly impossible.