So, those systems that do not purge /etc/yum.repos.d may end up with an empty file?  The yumrepo type does not always drop the definition into /etc/yum.repos.d/${name}.repo.  If the [${name}] is already defined in some other repo file (say /etc/yum.repos.d/cobbler-config.repo), then yumrepo will update the definition there and not create /etc/yum.repos.d/${name}.repo.