Microsoft has just updated the following KB Article:
System Center 2012 R2 support for the April 2014 Windows Server 2012 R2 Update
Summary:
Microsoft System Center 2012 R2 components are supported for the April 2014 Windows Server 2012 R2 Update (KB 2919355). This update can be applied to the latest System Center 2012 R2 workloads that are deployed either before or after the update is offered through Windows Update. Or, you can install this update by using your preferred distribution channels.
Full details at:
http://support.microsoft.com/kb/2949669