If I try to go to http://gentoo.mirrors.tds.net/pub/gentoo//releases/amd64/autobuilds/, it says forbidden as it doesn't appear to host those? This was discovered by going to http://bouncer.gentoo.org/fetch/root/all//releases/amd64/autobuilds/latest-stage3-amd64-systemd.txt and when it returned an redirect to tds mirror.
It seems that DNS record is gone.