People think the EU should make things easy by standardising, but really it's about regulations designed to benefit vested interests. For example we now have to use brown for live and blue for neutral in house wiring, BUT there is no standard for how houses should be wired, and regulations in France and Germany require that it is done totally differently than in the UK. Meanwhile the EU has no control over the IEE, who continue to put out insanely complicated regulations for electrical installations. Then there are the Part P building regs, which basically try to turn electrical work into a 'closed shop' like gas work. (If you've ever had any gas work done in the UK, it's like asking the Freemasons to perform some secret ritual for you.)
It's a mess, and that's one of the reasons we want Brexit, is to reduce the mess. Our own bureaucrats produce enough regulatory mess on their own, thank you very much.
As for this Wirebutter thing, the overriding question is, why would I want one, and what advantage does it have? AFAICS it's a gimmick, and a costly one at that. You can buy wirelessly switched sockets in sets of three for £12 or so. UK approved too.