I've just noted http://tracker.moodle.org/browse/MDL-32505 that has taken away a feature which I suspect is used very broadly by course designers attempting to overcome the Scroll of Death.
Summarising my understanding:
1. Displaying a single section is no longer possible UNLESS you have changed the 'Course Layout' setting to 'Show one section per page'.
2. If you attempt to link to a single section through adding the section ID to the URL when the 'Course Layout' setting is to 'show all sections' then it will ignore the URL and show all sections regardless.
This means, I think, that if I am a student and my teacher has decided to show all sections on one page, then I can't collapse them down to personalise my own learning space and focus on just the topic I'm working on. Similarly, if my teacher has set the course to one section per page then I can't expand out all topics to see the whole course (which is handy sometimes if I want to use text search in my browser to find a key word I know is in one of the topics, somewhere). I have been forced into consuming the course the way my teacher has set it up, and although I can't accidentally hide content, which was tricky at first, I also have less control over my own learning space - I am at the mercy of the teacher to view the course how they want me to view it, rather than how I want to.
As a teacher, although I can now elect to collapse down my topics and just show one at a time, or show them all in one hit, I can't build a custom navigation structure that lets me do both (i.e. I can't start out showing my students all topics and then guiding them to close all but one topic to focus on one thing). If I want this then I need to use a third-party course format like Collapsible Topics.
Is this a problem? Should it be reverted to how it was? To me - yes, it should be changed back, but I am keen to see if anyone else considers this an issue, and if so then I hope they'll vote/comment. If not, then I guess I'm wrong and this ticket will get closed soon enough
I am listing it as a bug however given that:
1. Its a removal of existing functionality done without any community consultation that I can see (please prove me wrong if I am); and
2. It will cause issues for users who have designed courses with custom navigation once they upgrade, with the only workaround being to remove the custom navigation, or at least change it (and the Course Layout' setting) so that it is either showing one topic or showing all - not an option for both.