What's the point of them?
They're slightly fatter than Europlug pins so won't fit in bathroom sockets when you go overseas, meaning you need to take a travel adapter. Some travel adapters for BS1363 will also accept the round pins of a British shaver plug, but most won't meaning you need to plug a shaver adapter into the travel adapter, how unsafe!
All UK bathroom "Shaver only" transformers will accept a 2-pin Europlug. All UK BS1363 "shaver adapter" plugs will accept a 2-pin Europlug. Shaver sockets overseas in non Euro places (eg Australia where Clipsal is king) will also accept a 2-pin Europlug.
Supposedly the British 2-pin shaver plug will fit in a British round-pin socket, but I've tried a 5 Amp and a 2 Amp socket and it will fit in neither.
So why don't we just abandon the round-pin UK shaver plug and provide new shavers and toothbrushes with a standard 2-pin Europlug instead?
I can see the Daily Mail headline now...