During API calls Nsx Manager uses moref-id values for the cluster object, which should not change when renamed.
Show cluster all lists the name and moref-id (domain-c123) of the clusters prepared for NSX.
show cluster domain-c123 lists the name and member ESX hosts
On the other side since it is a major parameter, may need to be tested in detail for the specific environment, since it could be used for Automation scripts, vSphere,Vsan, Vra, backup, Srm and other solutions beside NSX,
These links could be helpful: