"Unversioned" metadata (which can be modified without triggering the workflow) like tags and content privacy, are not automatically synchronized in the live workspace.
If I validate a content and set a new unversioned metadata, I have to create a specific event ID, and create an observer class handling the copy (and copy it specifically in SitePopulator in case the metadata is not stored in the unversioned composite, like content privacy).

A standard way of doing this should be implemented. Just having a "Unversioned metadata changed" event, on which a standard observer would copy the given metadata, could do.