As you mentioned its still possible to file a bug about xorg-server at https://edge.launchpad.net/ubuntu/+source/xorg-server/+filebug and since the package hooks are for source packages it seems that the bug could just be reported about the source package.
As you mentioned its still possible to file a bug about xorg-server at https:/ /edge.launchpad .net/ubuntu/ +source/ xorg-server/ +filebug and since the package hooks are for source packages it seems that the bug could just be reported about the source package.