Hi there .
While installing and updating a Server 2012 R2 at work I saw that WOU installs KB3038936 which is "August 2015 anti-malware update for Windows Defender", and although that's successful, it installs this update over and over again (because it's missing over and over again). This should be avoided because by default there is no Windows Defender on Windows Server (2012 [R2]). Maybe WOU could check for the Windows edition or check for the existence of a service named "WinDefend" something.
I added KB3038936 to the custom exclude list because we don't use Windows Defender on any machines at work.
Regards
Dalai