Nikon has released a detailed lens lineup chart that shows what NIKKOR Z lenses will be available all the way up to 2021.
By the end of 2021 there will be 23 native Z mount lenses available. Eventually, there will be lenses ranging from 14mm all the way up to 600mm. Currently, there aren’t many lenses on the telephoto side. The two telephoto zooms of note that are yet to come look to be the 100-400mm and 200-600mm.
With the introduction of any new mirrorless lens mount it is always going to take a few years for a substantial amount of native lenses to become available. It took Sony quite a few years to bring out a decent range of native E-mount glass, and we are seeing the same thing now with Nikon and Canon’s foray into mirrorless.