The Nikon Imaging Cloud has scheduled maintenance for February 19th:
Rumors about adding support for other Nikon Z mirrorless cameras have been circulating for a while – maybe they will finally materialize this time around:
Nikon Zf image found on Nikon Imaging Cloud – support coming soon?
Again: rumors about Nikon Imaging Cloud support for Nikon Zf, Z6III, Z8, and Z9 cameras