Be careful what you wish for. The Daily Mail readership already think ebike riders are the satanic spawn of Hitler and Ma Baker, and any increase would have them slavering with rage.
Aside from which, it simply will never happen because of driving licence and vehicle category harmonisation across geographical Europe, of which the UK is a signatory. It would require a change in law in every EU member state, then our domestic primary legislation, and then statute pertaining to ebikes. With the world as it is you have more chance of Elvis giving Lord Lucan a reacharound in Trafalgar Square than you do of every national lawmaker wasting time, money and resources on something so minor when so many serious issues currently require attention.
Get over it.