Hmm.
Interesting.
Without reading the interview you mention, a brief look at Hockney's photographic collage work (and it is interesting to note that it is referred to as collage, and not panorama) shows that there's clearly a strong influence here as to the technology available to (a) create the panorama or collage; (b) present it; and (c) how it is meant to be viewed.
Looking at the dates of the works on hockneypictures.com, it's evident that when they were created, the technology simply didn't exist to "properly" align, stitch, and blend multiple photographs into a single image.
When people talk about "stitching" these days, the desire generally is to stitch seamlessly, because the technology now exists to enable them to do so, and people go to great expense and great lengths to create huge photographic panoramas that a stitched and blended perfectly.
I can see how shooting a panorama from multiple horizontal locations, and presenting it in such a way that the viewer actually walks past it, could work very well.