I don't understand why a pedelec helmet needs to be specified for a higher impact speed than a regular cycle helmet. I routinely exceed 80km/h on my road bike when descending. Now I hate to think what coming off at that speed would be like but I doubt many commuters on E-bikes are going to get anywhere near that.
I can confirm coming off at 50km/h and on to the road is bad enough. A few years back a car door was flung open on me and the left side of my bars just caught on the door. Broke my thumb when it caught on the bar as I went over the top, but my NZ standards approved helmet did save my head/face when that was the first part of me to hit the road, the sacrificial layer lost a good chunk and absorbed the impact surprisingly well.
I can confirm that coming off at less than 50km/h and on the road is band enough. The helmet saved me from a lot worse so for higher speeds I would want a better helmet