It's easy to do if there are regions in the world that aren't so tightly regulated. Then they can just look at what works elsewhere. If USB-D comes out and the rest of the world moves to it, it's a no-brainer for bureaucrats to get behind the switch.
It's much more complicated if the rest of the world fragments into say... 3 different standards that are all better than USB-3, but are mutually incompatible.
The law would then have been reassessed in 2020, at which point some EU bureaucrats would have had to weigh "reversible connector" etc. on one hand, and "take the career fall for forcing half a billion people to buy new chargers" on the other.
Actually, I think (but I'm no lawyer) that if the USB-IF wants to standardize a new connector, they'd want to call it USB-C v2.0.
The law seems to implicitly defer to them to define "USB-C". If the consortium wants a new standard they could either reuse the name, or wait 2.5 years on average for EU approval or rejection.
I assumed the directive had some "go with the flow" upgrade path, but after reading the directive I can't see any wording to that effect.
If the USB-IF depreciated USB-C in favor of a USB-X the EU's directive wouldn't change, the only "upgrade path" appears to be that the commission will "asses" whether the directive should be changed every 5 years, starting in 2025.
1. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv%...