[Rover]

"The plan" looks fairly reasonable to me.
I'm a bit puzzled that both Canon and Nikon have time for releasing exotics though (RF 28-70mm f/2, 58mm f/0.95).
While I get the idea behind the S 85mm f/1.8, I'm not so sure about the sex-appeal of a 20mm f/1.8.
The S 24-70mm f/4 was also a bit of an odd decision (vs the planned 24-105mm f/4).

The 24-70/4 is a compact solution well suited (presumably) to the Z6/Z7. The 24-105 (I wonder why not the 24-120 as per the Nikon tradition?) will surely be more bulky.

I think a 20/1.8 is a good idea, both for astro and for lowlight shooting. I know my 24/1.4 (which occupies a similar niche) is only rarely used but when it is, I know there's no substitute.