[p_l]

Funnily enough, the first attempt at such legislation back when there was much less commercial use of internet kinda failed due to vendor pressure and allowances for continued use of IPv4 (this was specific to DoD/Government networks, and was supposed to migrate to OSI and its up-to 20 bytes addresses)

[jandrese]

Most government sites just set up Cloudflare IPv6->IPv4 translation frontends to check the box.

[count]

There's a mandate that backbones be dual stack. Basically nobody pays attention to it. https://georgewbush-whitehouse.archives.gov/omb/memoranda/fy...