Still, the issue isn't the presence of a throttle. It's the specs of the machine.
The idea that the law should be framed around whether or not the vehicle needs to be peddled is backwards. The relevant machine specs are what the legislation should address. Which is still, primarily, top speed. All incident evidence we have suggests that below ~20mph / 30 kph, even full automobiles see precipitous dropoffs in serious injuries, so that's the place to start. We see most places really serious about bike networks going reasonably further past that (25 or 20 kph). That's all reasonable. If you further want to have requirements on acceleration or weight, it's worth investigating that.
Having the legislation require peddling is just a way to create weird loopholes in the law. It's pearl-clutching and moral panic. And worse, it creates accessibility issues and can pressure people off the bikeped infrastructure who would've used it reasonably and safely back into cars.
The law should narrowly address the actual problem, not some tertiary smell the problem has created. The idea that a bike that has pedals is magically safer than an identical bike with an identical frame, motor, and everything which has a throttle is preposterous.
I am totally convinced an ebike with a throttle is safer and easier to use for its rider than one without one at any speed. I don't think they should be required -- because that's just silly -- but I think anyone the claiming opposite, that only peddled, throttle-less vehicles are safe, has fallen off the deep end.