God help us now...
...We're doomed.
I can see it now. FCC mandates IPv4 for "compatibility" reasons. Rest of world, running out of IPv4 addresses converts to IPv6. USA stifled.
Look, it could happen. Rotary dial telephones still work for "compatibility". One might think this is a good thing. Of course VoIP people don't do this (I just tried!).
So, yes WE'RE DOOMED (sorry for the Charlie Brown reference, baseball season is starting).