Here it is in a nutshell:
- Canon (1) — 100-500mm f/4-7.1
- Panasonic (2) — 70-300mm f/4-5.6 + Sigma 100-400mm f/5-6.3
- Sony (6) — 70-300mm f/4.5-5.6, 100-400mm f/4.5-5.6, 200-600mm f/5.6-6.3 + Sigma 100-400mm f/5-6.3 + Tamron 70-300mm f/4.5-6.3, 150-500mm f/5-6.7
- Nikon (0) — ...
Nikon's lens lineup still ends at 200mm. The promised 100-400mm and 200-600mm seem to have fallen out of sight and may not make it out in 2021. At the moment they remain silhouettes on a road map.
Given that these are supposed to be system cameras, Nikon is currently encouraging the perception as not being a "complete" system yet. Yes, we're only three years in, but it's illustrative that Nikon felt that the Z DX models should have a telephoto zoom option long before the full frame models. As much as Nikon wants to sell you a full frame camera, apparently they don't yet want you to use it for telephoto work.