Please find below the two documents that are used to update or determine if host to be rebooted or not depends on the type of installation:
https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.esxi.upgrade.doc/GUID-22A4B153-CB21-47B4-97...
https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.esxi.upgrade.doc/GUID-B21C1C99-E6D5-4719-A5...
Regards,
Sachchidanand
