I'm not sure if "make sense" is the term to use here. I do understand why showing all topics by default is not the current behavior of the app.
However, the current behavior of how the app's course navigation functions doesn't make sense (or is absolutely not intuitive) to users who have been using the Topics Format web-based course, because all of a sudden the behavior is different on the app . Users go to a course expecting to see the entire course and they do not. So what do you do to see the entire course? Well, on the web, clicking on the topic title acts as a link to that topic, whereas in the app, clicking on the topic title acts as the navigation method between sections -- so this is not intuitive when going from the web to the app.
In the end, there should at least be some type of explicit indication for users to "click on the Title" to change between sections while on the app. I think starting there would be a great start : )
The latest version of the app is quite amazing by the way!