I have Office 2016, including Outlook 2016, on Windows 7 Enterprise.
I've noticed that every time I minimize the Outlook window it closes the app. There's a demon that still runs and displays a yellow icon in the bottom righthand tray when you have a new email, but this is still a problem because I have to frequently reload Outlook, which wastes time. It also means I don't get my meeting notifications when the app has been accidentally closed.
I'm not sure if this is the intended behavior of the app, a bug, or some weird setting, but I'd like to fix it.
You have the option "Hide When Minimized" on.