When a user deletes a file from their computer the file will be removed from the DUDF and the NUDF based on the retention policy set in the Profiles Backup Selection.
Once this value is changed, it will affect all new and all existing backed up files. The DLO Agent on the client initializing the delete function. The client will run maintenance approximately once every 24 hours, however, if the client is uninstalled or not running for some reason, the files will never be removed.