We recently had 7 days at WBC. We had 3 full day lessons with the Blackcombe ski school. I was on new skis (which I love) but suspect would have learned almost as much on my older 5 stars. What was valuable for me was the reinforcement of the relationship between the snow conditions, slope, equipment, and the skills used to effect enjoyment of any given descent. That is, each action whether it is pressure, pivot, vertical movement, fore and aft balance, contributes to a particular result, and if the desired outcome is realistic (eg with my skill set and strength I would not attempt to clean carve a steep slope) then every turn is a learning experience.
This was achieved partially by drills that showed cause and effect, which showed me that as long as you know what you are trying to do, and are confident you have the understanding correct, then practice can be part of the free skiing experience. And that is why I had no complaint at all doing a whole run of side slips (forward, straight down, and backwards)
I believe a ski that makes it "easy" to practice various skiing skills does help, and using a ski that is completely wrong would diminish the learning experience, but that overall, lessons are more valuable than the latest gear