According to latest rumors on NR, the upcoming NIKKOR Z 85mm f/1.8 S lens for Nikon full frame mirrorless cameras is expected to be announced in later this month. And the Z 70-200mm f/2.8 S Lens is expected to be announced in later 2019.
According to latest rumors, one TBA lens in the Nikon Z mount lens roadmap is the NIKKOR Z 70-200mm f/4 lens. This lens will be a light-weight and cheap lens compared to upcoming NIKKOR Z 70-200mm f/2.8 S lens (Release date in late 2019). The release date for this lens is in 2020 to 2021.