(NVRAM) is the general name used to describe any type of random access memory which does not lose its information when power is turned off.
Many devices have a separate portion of place to store their information like a raid controller card, ethernet controller card, even amt firmware is a small nvram space storage.
Usually, when upgrading to a new hardware or you have a new configuration, it may detect hardware changes and may point this to you, similarly, a raid controller may give this alert when you have a different configuration.
But for motherboard, sometimes while upgrading the bios firmware, it will automatically clear the previous nvram and then load the latest code.
This is why sometimes when user encounters different weird issues, we advise them to do a clear cmos followed by the latest version of bios.
In your case, i would still do a cmos clear and then load the latest bios. But this is not something compulsory if you are not facing any issues.
All the best,