I am puzzled by this feature. I tested it on beta by collapsing the course nav menu in a course then going to another course. Sure enough the course nav menu was collapsed in the next course, thus I was stuck on the home page. In order to get to another tool, I had to expand the course nav menu, because the home page didn't contain links to everything in its body. It seems like a situation that will repeat itself for most users in most courses.
I would also like to point out something off about the rationale for the change:
Change Benefit
This change offers consistency with the behavior of the Global Navigation Menu and allows a user to set the state of the Course Navigation Menu.
There is an important difference between the global nav and course nav menus: the global nav is usable when it is "collapsed" (so perhaps "shrunk" would be more accurate), but the course nav is totally hidden when collapsed.
For me, this change just seems inconvenient. Am I missing something?