Hi,
Moiré / aliasing is a phenomenon inherent in the digitization of the image, and can be seen for example on a tiled roof (with a repetitive pattern).
To remedy this effect, the manufacturers put in front of the sensor, and associated with the infrared filter, an anti-aliasing filter which causes a small blur and thus eliminates moiré/aliasing. But of course, this is at the (slight) detriment of image quality.
Except error on my part, Nikon had made two versions of its D800 model. A classic model with an anti-aliasing filter, and a special D800E model without this filter. The D850 model is without filter, and it is convenient for the user to correct the (rare) images which present an effect too sensitive, by adding a little blur.
I don't know about the other manufacturers