Its typical Brexit pie in the sky combined with scaremongering. Pretending that there is something better (that doesn't exist yet) and that somehow, if there was, the EU would ban it. Neither is reality - there is no better charger out there, and if there was, perhaps the EU would also adapt that one? In the meantime, actual, the current situation improving, progress is being talk down. Charger norms are good for consumers and industry, and the environment. Nobody wants the piles of propriatary chargers we have right now. If something better is inventend, we, and the EU can re-evaluate at that point of time.
(Also as a note - afaik this is mostly about the plug. The EU say that all new portable devices have to be able to charge via a USB-C plug (the small new usb one). Afaik there are exceptions (of course), for example wearables where that would be impractical, such as wireless headphones.)