Ah. Just a blatant inaccuracy on wikipedia I take it. That does make a bit more sense.

Yep. gov.nl is in the PSL[1] and there are plenty of used subdomains (e.g. https://business.gov.nl/)

[1] https://publicsuffix.org/list/public_suffix_list.dat

As far as I can tell .gov.nl is only used for pages aimed at i.e. expats and businesses. Most services dutch people use simply have a .nl page like the digital id or filing taxes.