Nikon is rumored to announce a new lens tonight. I am not sure which lens exactly will be released, but it will probably be a prime:
Update – Nikon officially announced the Nikkor Z DX 24mm f/1.7 lens from the roadmap:
Nikon officially announced the Nikkor Z DX 24mm f/1.7 lens from the roadmap
I expect the 200-600mm to be announced in June/July. Stay tuned for the surprise in a few hours.