If it’s about limiting it to bicycle type speeds, that could be done separately.

Yeah, but at least in some legislations, there already is a class of vehicles that is limited to those speeds but isn't classified as a bicycle. In Germany, a Mofa is a motorized bicycle but requires a helmet and a simple license and insurance.

I guess the idea was to include electric bicycles into the bicycle category only with some strict distinctions to avoid blurring the line to already existing motorized two wheelers. And I do like that I can ride my electric bike everywhere I can ride a non assisted bicycle and without any stricter rules for equipment etc.

As an aside, IMO riding a bicycle or any vehicle on roads as opposed to a vehicle specific path for any considerable length of time should require having to get a permit and maybe even a license and insurance, because participating in it is much more about the flow of traffic than the characteristics of a particular vehicle.

That would be a huge loss of freedom though, insurance and thus license requirements would raise the barrier to entry massively which is exactly the opposite of what you want. Same with requirements for helmet or permit and it would seriously limit the independence of teenagers. There just isn't a separate path away from car traffic everywhere.