The referenced Heer & Robertson paper discusses chained animated transitions that take you from one type of visualization to another in a way that explains the relationship between the two visualizations. The usefulness of chained transitions is debatable, but it is important to note that Chart.js's implementation seems to starts from nothing and animate to the final position of a single type of chart. This is not really adding: "empty" is not an interesting state, so the transition is frivolous. Moreover, because it forces pixel movements on the page, the users are left with looking for meaning, and are distraction so I'd contend this impedes with overall usability. And yes, it is great eye candy, and the corporate powerpoint junkies will probably love it, but remember: they also love those 3D pie charts.
