NikonRumors published an updated and more detailed list of Nikon Z6 II and Z7 II camera specifications:
The new Nikon Z6 II will start shipping in mid-November, the Z7 II in January 2021 (?)
In 2021 a new 4K/60p with 1.7x crop will be released with a firmware update
Expect up to 30% price increase over the Z6 ($1,797) and Z7 ($2,497) based on your location
The Z6 II and Z7 II camera sensors are the same as in the Z6/Z7, the improved AF is coming only from the extra/new processor
The new Z6 II /Z7 II battery grip will be called MBN-11
The Nikon MBN-11 will have a shutter release button as previously reported and the electronic contact will be located in the battery compartment (similar to the Nikon D80/D90 grips)
14 fps for the Z6 II and 12 fps for the Z7 II
Most improvements are in the eye and animal AF area and some tweaks in the AF-C mode
AF improvements include low light situations, wide AF area, AF tracking, video recording
New or improved energy-saving mode
You will be able to update the Z6 II and Z7 II firmware via SnapBridge (Wow! finally!)
Improved buffer (as previously reported): 99 with the Z6 II and 57 with the Z7 II
You will be able to reverse the control/focus ring direction with one of the camera functions