.widget-title vs. .widgettitle in Toolbox theme and default WP widgets

Got an observation about the class name of the widget titles used in Toolbox. In functions.php it’s declared to be ‘widget-title’ (as more themes are using this now) but the default WordPress widgets, which are called in 404.php, still use ‘widgettitle’.

Since Toolbox is maintained by Automattic, I was wondering if there’s any way to make the default widgets use ‘widget-title’ class name. Or I could suggest that the theme functions.php goes back to using ‘widgettitle’.