While this addition is a good thing, there's a potential downside: The DX Line could be without an electronic viewfinder.
The next Nikon cameras to be added to the Z Mount series may likely be a Nikon DX APS-C line of cameras, according to a report from Nikon Rumors. The cameras, which will replace, or at least mirror, the mid-range DSLRs like the D500. But one thing that may be missing, is an electronic viewfinder.
According to the report, Nikon is set to announce two new Z Mount cameras, including a prosumer grade camera, that may be called the Nikon Z3, and a lower end consumer-grade Nikon Z50, both with an APS-C image sensor. The prosumer model will shoot 4K video and shoot burst images at 10 frames per second.
The speculation is that this lower end Z mount camera may likely either replace or mirror the Nikon D500 DSLR, giving a higher-end performance at a lower price.
Meanwhile, designs that have been leaked from patent applications, indicate that the APS-C cameras will come without a viewfinder, and have a larger 4" LCD as it's the main way to compose your image. Canon did a similar design recently with the M6 Mk. II, where a viewfinder was omitted from the base design, but in that case, Canon is making available an optional removable electronic viewfinder that fits onto the camera's hot shoe.
Could Nikon do the same? Perhaps, but it feels unlikely. The Z3 could, however, have a 24 or 26MP image sensor and single SD or even microSD card slot, while the lower end Z50 will go with a smaller 20MP APS-C image sensor, have a smaller 3-inch LCD that pulls out and pivots, and will use the new Nikon EN-EL25 battery.
Whatever the name, Nikon is also expected to announce two DX-style "collapsible kit lenses" including a Z mount Nikkor 16=55 f3.5-6.3 zoom and a 50-250mm f4.5-6.3 zoom. An official announcement is expected "soon." Which could be anytime before Black Friday in November. Since these are designed to appeal to consumers and prosumer markets, Nikon is not going to want to miss out on the holiday shopping season.
Further, Nikon Rumors says that, moving forward, single digital Z mount models will be full-frame mirrorless models, while double-digit cameras will be crop sensor DX bodies. But if that's the case, do not expect Nikon to use the Z3 nameplate for an APS-C camera. To do so would just be confusing for consumers.
But remember, this is all speculation until made official. So stay tuned.