When PMImport ("Meta Data Import" in 7.1 SP1) runs again, it will detect the updated patch and download it. If you checked the box for 'Automatically revise Software Update policies after importing patch data', then the policies will be updated automatically with the new revision. This will happen on the same PMImport schedule that would download new updates, configurable in the console.
If they're not running the new patch, it must have the same detection and applicability rules as the old patch. In this case, you would want to roll back the old patch using a Run Once uninstall policy, after which systems will show vulnerable again and receive the updated patch.