Nothing new of course, sprung hubs have appeared a number of times, notably in some Triumph motorbike rear wheels in the 1950s.
One criticism of this realisation is that it's direct vertical spring action means inefficient pedalling through thrust energy losses, though that will be less important on higher powered e-bikes when less energy is put into pedalling. Another criticism I have is the lack of damping in the system. Lastly, I'm not confident the softer sprung front wheel would have sufficient lateral stability in stressed cornering conditions.
If suspension is wanted I think it's best to stick with front telescopic forks and a thrust countered link suspension system for the rear.
