Yes, "Remember The Time", "Black Or White", et cetera were shot on film.
Also, 1080p resolution is not anywhere close to 6 million pixels. It is just 1920x1080 ~ 2 million.
Sharpness of actual image on film-"original" may differ significantly. However, mass-production films for cinema theaters have just no more than about those 2+ million pixels TrueHD+ (1080p or 2520x1080 with 21:9 aspect ratio) resolution.
Also, his OFF THE WALL videos were not recorded on fim were they? I dont detect any grain or anything like for the THRILLER album videos...They look like they were recorded on some sort of video medium not film..