I believe Nikon's aim is to gradually ween seasoned photographers off the venerable F-mount which, for all practical purposes, held back the adoption of the optical formulas that existed on drafting tables and work benches but couldn't surmount the ancient flange-distance. New photographers or system adopters will hardly know the difference or care much, if at all. I appreciate Nikon's long standing dedication (or am I being naive?) to backward compatibility. But to survive, the wider throat diameter of the new Z-system mount was, is, a necessary development. I'm just overjoyed I may continue to use legacy Nikkors as surely as hipsters and artistes will discover all manner of classic-crap with which to indulge their muse. (Holga lens [sic] on a Z6, anyone? Come to Brooklyn, next year... )
One last thought: Will the image circle of the new lenses cover medium format, therefore allowing for a one-mount, one-lens, universal system for Nikon FX and medium format digital camera development? Just curious. The mount diameter certainly appears wide enough -- but if I knew anything I wouldn't be asking.