Even without NAT, the same hole punching techniques must be used for IPv6 since there is usually a firewall blocking inbound traffic. Only in CGNAT type scenarios where the network behind NAT is still "WAN" will be helped by IPv6.
And hole punching gets a lot simpler when you’re behind NAT since you don’t need any kind of rendezvous server to determine port mappings.
In other words, IPv6 does help substantially—the same hole punching techniques are not needed.