Well it was Nikon's hype machine that got the frenzy going with terms like revolutionary camera...and then release nothing revolutionary at all.
I agree that Nikon Z is a good and only slightly risky evolutionary step rather than anything revolutionary, but then again maybe I have a weird idea of what is and is not revolutionary. Amongst the more worthily revolutionary things that lie behind the Z system, and the companies who first bought them to cameras:
- digital SLRs (Kodak, and arguably Nikon for going beyond "Franken-cameras")
- sensor-based stabilization (Konica-Minolta)
- active pixel CMOS sensors (Canon)
- Live view (Olympus and partner Panasonic, initially in Four Thirds DSLRs)
- mirrorless system cameras (Panasonic and Olympus with Micro Four Thirds)
- an EVF in live view cameras (Panasonic)
- column-parallel ADC on CMOS sensors (Sony)
- on-sensor PDAF, mostly closing the gap with SLRs on AF performance (correction: Nikon, not Sony?)
- five axis IBIS, clearly establishing IBIS as superior to lens-based IS (Olympus)
and maybe
- abandoning essentially all backward compatibility for the sake of a new modernized lens mount and system (several times: Canon EOS, Olympus Four Thirds, Fujifilm X system, etc.)
What strikes me as most clearly mere evolution, not revolution, is doing something that has been done for some years by several camera makers, but
in a different format. And yet some seem to think of Sony's moving mirrorless to 36x24mm as revolutionary, rather than its more legitimate innovation(s) listed above.