I'm not convinced that this bit in the article is correct:
For example, some cyclists with disabilities find it easier to use e-bikes but are unable to pedal unassisted to the 4mph speed at which, under current laws, the electric motor starts up.
As I understand it the 4mph limit is the speed up to which the walk assist function can operate where pedalling is not necessary. Above 4mph you need to pedal to get electric assistance.
Yeah, it only needs to sense you pedalling to provide assistance, though I note barakta's Falco system does have a minimum forward speed threshold too (intended for use without a crank rotation sensor, in regions that permit it).
I'm strongly in favour of the move to provide hand-throttle operation, as this is a game-changer for some disabled people. As a road user, it matters to me not a jot whether e-cyclists are pedalling or running on motor power alone.
Similarly, I don't care about power rating. 500W is within the acceleration capabilities of a fit cyclist, and the speed limiting still applies, so all it does is make cargo-hauling more practical, and give a bit more thermal headroom for hill climbing.
What would be more interesting would be a 'speed pedelec' classification, which seems like it would be deeply unpopular with the government and gammonati.