In the case of the audio driver, the version string that is included with the version that is downloaded from Windows Update appears to be different from the version string of the latest driver Intel has for download.
They will be peeved with me for saying so, but I don't trust and will not rely on the Intel Driver Update Utility. This utility does not even support all of the drivers that the NUCs require. I separately download and install the drivers from Intel's Download Center. Search for your NUC and use the (much larger) list of the latest available drivers...
Thanks for your help.