This will surprise exactly no one, but we have official word from Bill Claff’s excellent PhotonsToPhotos.com measurement site that the new version of the Nikon Z7 has almost exactly the same dynamic range capacities at various ISO settings as the original version.
Nikon joined Sony in its revision of the A9 and Canon with its the revision of the 6D Mark II in releasing eagerly-anticipated camera upgrades that comprised mostly packaging.