The vault looks a little bare when it comes to centos-release source files there are just 3 of them. Most in the distribution are carryovers from 7.6 but there are a few new ones:

centos-release-ceph-luminous-1.1-2.el7.centos

centos-release-configmanagement-1-1.el7

centos-release-gluster-legacy-4.0-3.el7

centos-release-gluster41-1.0-3.el7.centos

centos-release-nfv-common-1-5.el7.centos

centos-release-opstools-1-8.el7.centos

centos-release-storage-common-2-2.el7.centos

centos-release-virt-common-1-1.el7.centos

Neale Ferguson