Context:
People have been asking for IPv6 Support on GitHub since years (probably a decade by now)
... and someone even got so annoyed that they decided to setup a dedicated website for checking this: https://isgithubipv6.live/
I'm using ipv6 when I occasionally connect to Yggdrasil.
And I think I'll use ipv6 if we ever need to build a new earthnet.
It's a fine technology.