I made a mistake earlier today – the Nikkor Z 800mm f/6.3 lens is not in stock at B&H yet (sorry), but the new Nikon Z30 camera is now in stock in the US for the first time (the base model and two lens kit will be in stock next week):
Update: the Nikon Z30 camera with NIKKOR Z DX 16-50mm f/3.5-6.3 VR Zoom and NIKKOR Z DX 50-250mm f/4.5-6.3 VR lenses is now also in stock with a $100 instant rebate.