I was working at a start-up this year on e-bike share program prototypes, and off-road gov't contract prototypes.
The article makes claims, and has left out some details of this wheel. It's been announced in Europe a while ago.
Power: from my development mule, it takes 800W from a hub motor to reached that max speed with a 48V pack.
20 mph is the max speed mandated by the Federal government for e-bikes used on public roads.
IIRC, this wheel is supposed to be recharged by the rider's input and when descending, relieving the need to plug it in. It's meant to give assist, but you still must pedal.
I think that may be a good thing to not make the rider 'lazy' and lose the benefit of cycling.
The range is limited, based on the restricted volume of the wheel, battery capacity isn't much.

It'll sell, because people will think it looks cool.