I had noticed this as well, but I'm also seeing an issue where it will create the html versions of the help files, but it doesn't finish.
The last html file in my list after this happens is:
C:\Users\sbarbe\AppData\Local\Temp\webhelp.C\cmdlet_Reset-NcNameServiceDNSStatistics.html
but if you run get-nchelp, the list continues until the end with the write-NcFile command, which I presume should create an html file:
C:\Users\sbarbe\AppData\Local\Temp\webhelp.C\cmdlet_write-NcFile.html
So it looks like it is doing part of what it is meant to, but it fails to complete and launch the browser. It also does not specify which file it cannot find. Is it looking for cmdlet_Show-NcHelp.html ?