IPv6 is already backwards compatible though. There's a /96 of the IPv6 space (i.e. 32 bit addresses) specifically for tunneling IPv4 traffic, and existing applications and IPv4 servers Just Work™ on IPv6 only networks, assuming the host operating system and routing infrastructure know about the 6to4 protocol and are willing to play ball.
Oh nice. Does your system FINALLY provide enough addreses for every Planck volume in the observable universe? It’s been frickin amateur hour, this internet thing.