This one puzzled me, too, Gareth.
The key is that these are the blocks that will appear when "Collapsed Topics" is selected as the "Course Format" when creating a new course, and not when simply switching from a different Course Format (e.g., Topics) to Collapsed Topics.
The key is that these are the blocks that will appear when "Collapsed Topics" is selected as the "Course Format" when creating a new course, and not when simply switching from a different Course Format (e.g., Topics) to Collapsed Topics.