This is insane, was there additional software installed by your employer that might have conflicted with the updating process?
In my case we have lots of remotely controlled macOS updates that get triggered and supervised by the company I work for.
This is a now well-known bug having to do with multi-monitor setups or changing the refresh rate of the internal panel. MDM policies and other software couldn't write to NVRAM in a way that would cause this issue without the help of a bug in Apple's code.
I wouldn't be surprised if MDM policies caused some funky shit to happen. I couldn't use the migration assistant on one machine because the policy blocked the recovery OS; it just silently failed and booted you back up into your main account.