JFYI:
I noticed that 8.2.2004/ is not linked into http://vault.centos.org/centos/ but available under http://vault.centos.org/8.2.2004/
# grep content /etc/yum.repos.d/CentOS-Sources.repo |head -1 baseurl=http://vault.centos.org/$contentdir/$releasever/BaseOS/Source/
# cat /etc/yum/vars/contentdir centos
-- Leon