edit: luddite not meant in a derogatory sense. We need luddites!
> At least 80% of IP-enabled assets on Federal networks are operating in IPv6-only environments by the end of FY 2025
https://www.whitehouse.gov/wp-content/uploads/2020/11/M-21-0...
Like, the US Govt has been 'going to move to ipv6' real soon now since I was a baby engineer.
> In August 2005, OMB issued M-05-22, Transition Planning for Internet Protocol Version 6 (IPv6), requiring agencies to enable 1Pv6 on their backbone networks by June 30, 2008. This policy outlined deployment and acquisition requirements. In September 2010, OMB issued a memo entitled "Transition to IPv6," requiring Federal agencies to operationa11y deploy native IPv6 for public Internet servers and internal applications that communicate with public servers. Specifically, the 2010 memorandum required agencies to upgrade public/external facing servers and services (e.g., web, email, DNS, ISP services) to operationa11y use native IPv6 by the end of FY 2012; and to and to upgrade internal client applications that communicate with public Internet servers and supporting enterprise networks to operationally use native IPv6 by the end of FY 2014
So that 2005 memorandum laid out groundwork to setup basic ipv6 backbone networks, and mandate purchases to be ipv6 compatible. That has been happening in the past 15 years so that now we are at the point that the latest memorandum is aiming to transitioning to IPv6-only deployments. If they set the requirement to be largely IPv6-only in just couple of years, then they must believe that there is good readiness for that at the moment, and I would like to think they have done their homework here.
You can still use IPv4 internally if you have legacy devices, but anything on the Internet has to use IPv6. You have about 5 years to get it done. There are lots of solutions for specific use cases including stuff like ::ffff:1.2.3.4 and IPv4/IPv6 NAT devices. Most of which won't be as necessary as people think because IPv6 support is already widespread everywhere except ISPs.
No need to worry about silly things like the popularity of such a move, the cost involved and the mountain of e-waste produced.