Please also see related post:
The following details how to repoint a vCenter VCSA using an external PSC within the same site to a different PSC FQDN. One reason for completing such a task is in the event of your active PSC failing you can simply repoint VC to a second PSC in the same site. The reason I completed such a task was part of a VxRAIL VVD deployment leveraging a load balanced PSC config which required to repoint the VxRAIL management VC to the LB FQDN.
If you wish to confirm the current configuration status of PSC & VC simply navigate via the Web Client: