Right now you have to go to your account settings in order to make a global announcement like this:
This is not very intuitive, I would've never have thought to find them in settings since this is something that is not a setting at all. It makes them feel like they are being buried.
I suggest we move them to the navigation pane so you can find them quickly, saving a lot of time for those of us who make a lot of global announcements. Here is my example of what it would look like: