When syncing new source packages from Debian, we most commonly want to override packages from Debian's main component into our universe component, and packages from Debian's contrib or non-free components into our multiverse component. At present, we do this by hand. However, this is rather laborious and sometimes results in new packages going into main by mistake; while this isn't harmful long-term since we have automated reports to detect packages that should be demoted, it often wastes time as builds fail due to ogre-model constraints.
When a new source or binary package enters an Ubuntu queue (i.e. at process-upload time, not queue accept), its component should be set based on the following mapping from the component in the .dsc or .deb respectively: {'main': 'universe', 'contrib': 'multiverse', 'non-free': 'multiverse'}. If the component in the .dsc or .deb is not in that mapping, then it should default to universe. The archive administrator may still choose to override this to something else and that choice must not be overridden. None of this should apply to source or binary packages that already have overrides in the archive.
it's simple to set default_ overrides_ map to NEW packages in upload time.