In the video it said something about running data through a neuromuscular model. And: "Our AI uses machine learning algorithms to adapt to a user's walking gaits, making them an extension of people's legs."

For all that, the person's gait looks strange to me, like they aren't using their muscles normally. Maybe they are focused on landing the skate evenly on the wheels, or not getting off balance? Walking gait involves heel-strike and toe-lift-off phases and I would think if you mess with these they aren't going to feel comfortable after wearing a while.

It is likely an pair of accelerometers that learns the user’s gait pattern. Like most other AI claims, it has nothing to do with actual AI.