This went up on YouTube many months before AmputeeOT's "Lego Leg" video. It has a lot of views, but according to the stats history, there was no spike at all in connection with the Lego Leg video. I would think it would be a natural related video suggestion.
The chair itself is pretty cool, and looks to be about as practical as the Lego prosthetic.
One thing about disability awareness gimmicks is that it is very hard to predict how people will process them. People seem just as likely to come away with a message of pity or sympathy as they are to see capability and empowerment. You can see that in the mix of comments on AmputeeOT's videos. I wonder what long-term effect these Lego videos will have on people's perceptions about disability and adaptive equipment.