Maybe true in Eastern Europe. Though Elan is in Slovenia. Our ski school had Elan psx short carving skis. In 3 lengths, 113, 123, 133, though that progression was never really used. We just used the 123’s iirc. That was probably year 2000. The 99/00 year was a sea of orange Volkl P30’s, the last iteration, and best, of the P30’s. I’d say that was the last year you saw gs skis, or slalom, dominate as the choice of most good skiers. After that the alternative choices, which had been there a few years, dominated.
The video is really advanced skiers learning carving. Almost no beginner is going to go from a heel pushing wedge carve to both shins parallel and working simultaneously in a carve. There’s exceptions maybe for athletic hockey players or rollerbladers.
Witherell had all sorts of excercises with a one ski carve. We used to do flying wedges just carving on the outside ski. But that’s not intermediate/advanced.
The fundamentals in the video, pushing the outside ski, full body rotation, are all considered negative movements. Ironically, they kind of teach separation by going straight and pushing the outside ski out. Then it all goes away with the body rotating.