I think learning to foil on flat water, 12-15kts, wide board, super stable foil like Starboard Freeride, will make learning very easy. Those conditions in the video and gear used would give most first time foilers a totally different perspective about foiling (especially if never windsurfed before).
That they were even able to uphaul a 125l board in those conditions as first time windsurfers is commendable. I applaud their efforts.
Crux of the video, though, like the Aaron McIntosh interview floating about, is that windfoiling can be done very early in the learning curve. This clearly wasn't the wisdom just a couple of years ago. It's like when the Starboard Go came out and everyone could skip that awful part of the learning curve of buying something to learn on for the first few months that you'd never use again.