From the position of them in the illustration and in the article I’m going to call them ‘slats‘. Flaps are at the trailing edge of a wing surface.
Scientists have discovered that the flying dinos might have used a thumb like bone on their wings as a slat to provide more control over their flying. Some birds do this today and as more and more research shows that their ancestors share a commonality I’m sure that more of these parallels will be found.