It's more than that. In one of the videos they mention it works even at wide open apertures to cancel out the effects of the AA filter... so perhaps some sort of 5DS R effect is included. We won't know if, or how well, it performs until Bryan get's his hands on one.
The 1.74x crop on the 4K video has me confused. Why didn't they throw a few more pixels on the sensor, and make it do a 2x2 downsampling to do 4K w/ less noise. Perhaps they designed it expecting to downsample by 1.74x, but then didn't like the result, and in the end chose to crop it and use "pure pixels" instead. That's the only big flaw I see, from the specs.