archive-restore --db-url flag not working in D7

archive-restore's --db-url flag does not seem to work for Drupal 7 restores. I'm not sure whether this is intended. The help documentation states:

--db-url                              A Drupal 6 style database URL indicating the target for    
                                           database restore. If not provided, the archived            
                                           settings.php is used.             

This suggests to me that a D6 style MYSQL connection string should be used when entering the command, but it isn't clear whether this will be parsed into a D7 db array for D7 sites.

If the --db-url is intended for D6 installations only, then the help text should be more clear. If it is supposed to work for D7, then this is a bug. It currently just appends this to the end of the settings.php file in D7:

// Appended by drush archive-restore command.

$db_url = 'mysql://user:pw@server/dbname';