Hi @kewing,
To start off, I wouldn't really say that changes can be pushed directly to courses through commons. When content in commons is updated, teachers using that content would see a notification that the content has been updated when they go back in commons, and prompted to update their course to the new version. In all likelihood, I think most courses wouldn't get their content updated using this method.
If you want to centrally control content and be able to push an updated to courses with a single button type of interface, I think Blueprint Courses would likely be the solution for you. There is a nice Blueprint Courses Overview video that covers the basics of what Blueprint Courses are and how to set up and use them. If this seems like a fir for you, and you need more detailed info, here are some guides that may be helpful:
I hope his info helps!
-Chris
