I think there's different approaches. Apple, for instance, approaches MVC that way (controller updating the view, with the view having no knowledge of the model).
Right, there are different ways of doing it. In general, an arrow/line between Controller and View is better understood as "there is some type of communication"; then, different variations of the same design will use different forms of communication (observers, data binding, the controller references the view, the view references the controller etc).