Just guessing, don't really know:
The reverse loading of plates in the barbell ad might just be a advertising ploy to catch the eye of people. Something different in showing their product. Probably a lot of competition (as there is today) in the fitness/health business, back in the day. Doubt that the Schmitt company was big time (guessing again) so needed a different approach to sell their stuff. The DB's & BB's, in the ad, do look slick, and kind of cool, compared to a lot of the other older barbell ads, at that time. Would not think anyone is going to workout that way the BB/DB's are shown. Starting with 1 1/4 plates, and working up from that, is defeating the whole purpose of the progressive load idea. But who knows, other crazy stuff out there.
We are still using some Vic Tanny and Paramount plates, where I workout at. Bars break but plates never seem to die. Those iron shoes (don't know the right name for them) are really something else.