Such schemas cannot easily be refactored without removing the benefits of sharing. Refactoring would require forking a local copy, which for schemas intended to be treated as an opaque validation interface with internal details that may change, eliminates the benefit of referencing a separately maintained schema in the first place.

consider a situation where the branches of the oneOf are separate schemas owned by other entities (and therefore impossible to refactor without forking), which are intended to provide an opaque validation interface (and therefore may change internal details without warning, but without changing the desired validation outcome) and are included by $ref