Nuc7 iXXXX had supported internal Wifi. After that, it was not supported. You were able to use USB Wifi dongles, maybe an internal card, but, I never tried that.
As far as I know, there wasn’t any changes to the OS, just RoonServer in 1.8. So, there should have been no changes to WiFi, and there isn’t on my box. As you can see, I still have the Wireless tab. ( I have a NUC7 i5, fyi)