I've definitely used them in the way the article describes. Think about an API that gives a list view and then a detail of an object that has more properties than are sent in the list view (maybe because they are expensive to compute or maybe just to save bandwidth). This scenario can definitely be more accurately modeled with interface inheritance than with optional properties.
Okay your answer is more illustrative to me of the problem and solution. Totally agree, if you've got a list view and detail view those should be separate classes. Though my personal take in that senario is you might be better off using TypeScripts mapped types to define a subset of your detail view as a list view.
