Unfortunately it's no.
The problem is type approval, manufacturers have each bike model approved as an e-bike/pedelec and it costs them quite a lot of money. Technically a bike with a kit added should be single type approved before use on the roads, but while they are legal anyway no-one bothers.
Once throttles aren't allowed, any transfer of a kit to a bike creates a new vehicle which should be taken through approval, and when that's after the legislation change, it wouldn't be approved with independent throttle control.
The regulations can be circumvented with a complete bike though, since parts can be repaired/replaced for ever and the e-bike would still constitute the same vehicle.
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