ARIN, etc can force their clients to implement IPv6 if they would force everyone who wants to keep IPv4 addresses to use at least the same number of subnets for IPv6.
But this is only one side of the medal.
The ones providing the internet access to the consumers don't need anyone and cannot be forced to do anything (ok maybe goverment).
As long as the consumers cannot use ipv6 nativly the whole IPv6 discussion is useless.