We are in an multi-site cross-vCenter configuration, and we want to rename the Cluster at 1 site. We run ELM so we get all our other non-nsx datacenters and clusters, and most are named the default "Cluster" at one site, so we want to distinguish our NSX cluster, so its easier for us on some things.
NSX is smart enough to use object identifiers, instead of names. So renaming a cluster shouldn't cause any problems.
I have just tested this in the lab by renaming a cluster from Compute Cluster A1 to Compute Cluster A01 and the new name was successfully reflected on the host preparation tab: