Standard content and rights metadata schemas and vocabularies should have authorised, public mappings which enable terms and data to be automatically transformed from one standard into another.
As with other identifiers, it is neither possible nor necessary for everyone to use the same schemas and terms, although the more common usage there is, the better. What is needed is for authoritative mappings (authorised by those who govern the schemas) available as services supporting automated “translation” of metadata.
Note that terms in controlled vocabularies are identifiers, as they are unique names within their domain and type. When expressed as URIs they just become more identifiers in linked data.