We could see another higher end DX body that is targeted at higher end birding and sports with one of the newer higher megapixel sensors, like the 40mp range that Fuji is using or something newer with a higher readout speed. Something like that would surpass even the Z8/9 for that purpose. Which could also be a reason why it would not be made. APS-C sensors are not that far off of full frame image quality at all these days so that could be a dangerous camera to put on the market. But it would surely sell well and instantly be one of the best birding combo's with Nikon telephoto lens range.I wonder if they are thinking ahead about a higher end DX body? Nikon likes to reuse bodies or at least minimize changes. It affects the internal components as well as the shell. If they are anticipating a higher end DX, it would have dual card slots, faster readout, IBIS, etc. - and would require a larger body. This might be that body size - or pretty close. EXPEED 7 has the horsepower to deliver whatever is needed in a higher end DX body.
The Z50ii seems to be a major update to the Z50. There is a lot being delivered using EXPEED 7.
I'm hearing that Nikon is still not reached the limit of what EXPEED 7 can deliver for any camera - including Z9. If they can deliver more via firmware, it's worth it to wait another year for EXPEED 8. The economics for Nikon work very well if they can continue to sell Z8 and Z9 cameras while introducing a bunch of other cameras.
This Z50ii is a lower price point camera with compromises. I think people are expecting something more from it. It's a $900 camera and honestly offers a pretty good set of features at that price range. Just look at the competition at that price range. It's positioned well for its price point.