For me 32 MP on a FF sensor are useful only in very few application. Landscape photography is not one of those. Diffraction, micro-motion, CA, and lens resolution do not permit to take advantage of the full detail and to have a clean image will be wise to downscale. In addition high ISO performance are worse for sure.

I am not worried with the samples of 1DX, they are all JPG generated in camera and applying a picture stile. All photo at high iso are without noise but also without detail due to the picture style. Likewise in the action photo the red shirt in the background has a lot of artifacts, due to the jpg compression.
We must wait a RAW file in order to judge.

For me it is much better to have a 18-22 mpx sensor (also the 16 mpx of d4 is excellent, and 24 is the high limit IMHO)