Report transformations are customized versions of built-in financial reports tailored to the requirements of specific locations. Often, they put a report like the Tax Summary into a form needed for official tax filing in a jurisdiction.
When a report transformation is improved, all users of it should use the new version, of course. But no direct action is necessary except to update the version of Manager in use. Cloud edition users are updated automatically. Server and desktop edition users should update to the latest version. All installed report transformations will automatically be updated.