Commits after Oct 16, 2019 to https://github.com/gentoo/devmanual.gentoo.org have not propagated to the https://devmanual.gentoo.org website. Compare for instance: https://github.com/gentoo/devmanual.gentoo.org/commit/988392156daae34427906e98609d1dd1fe4970a5 with page at: https://devmanual.gentoo.org/general-concepts/mirrors/index.html
Nothing much we can do here as the devmanual team. CC'ing @infra.
Looks OK now. Probably stuck in some cache as I doubt there was any manual intervention.