Problem Description
In case of you renamed a Failover Cluster in Failover Cluster Manager which is connected to a SCVMM 2012 R2 you will see that the renaming will not be reflected in SCVMM 2012 R2.
Solution
Under these circumstances you can basically rename the Failover Cluster over the VirtualManagerDB > dbo.tbl_ADHC_HostCluster > Name Column as follows.
1. Connect to the VirtualManagerDB via SSMS. 2. Expand tables and navigate to dbo.tbl_ADHC_HostCluster. 3. And rename the Failover Cluster under the Name column.
1. Go to dbo.tbl_ADHC_HostCluster.
2. Find your Cluster Name under the Name column, rename and save it.
Good luck !