It looks like Nikon is trying to fire up interest in the 850 and trying to blame it on a leaked presentation. In any case, if these specs hold true, this is going to be on heck of a camera.
45.75MP FX full frame CMOS sensor
180,000 RGB sensor that’s same as the D5, with better face detection and enhanced scene recognition
Native ISO range of 64-25600 (expandable to 32-108400)
153-point AF system with 30% more frame coverage than the D5
Center AF point -4EV, and all others -3EV
8K timelapse shooting
4K UDH video recording in FX with no crop
51-photo buffer when shooting in 14-bit RAW
3.2″, 2.36-million-dot tilting LCD touchscreen with improved gesture control
7fps continuous shooting standard, 6fps with autofocus, 9fps when using a battery grip
30ps at 8MP using the electronic shutter
RAW can be small, medium, and large resolutions
0.75x magnification viewfinder, the first for a full-frame DSLR
Focus stacking. Camera can shoot up to 300 photos with 10 levels of bracketed focus from nearest to infinity for software to stack afterward.
Natural Light AWB achieves better white balancing in natural light
Completely silent electronic shutter while shooting in live view.
There’s no low-pass filter
Dual SD + XQD card slots