Update 30-01-2017: UR#12 for SCOM 2012 R2 is available now for download. Go here for more information.
Also noticed on the Microsoft Update Catalog that Microsoft is in the process of releasing Update Rollup #12 for System Center 2012 R2:
And again (like UR#2 for System Center 2016) only SCVMM and SCOrch are ‘touched’ but I am pretty sure UR#12 for other System Center 2012 R2 components will be available soon as well.
I’ll update this posting ASAP when there is more to share.