It doesn't have to be that way, because about 70% of all decisions are made in the EU parliament, and then confirmed in national parliaments - and each country has a representative in the same parliament in relation to the number of inhabitants. This means that decisions are made by the largest countries such as Germany, France, Spain and Italy, the smaller countries mostly just adopt laws.
I am not sure about how implementation of EU law works. I can recall one EU member state that was blocking aid for a non-EU state when all other nations voted in favour. Only when they received some benefit for their own state did they allow the bill to pass.
However, considering the existing and new regulations in the EU when it comes to cryptocurrencies, I am not at all optimistic that they will take the same position as the US in this matter.
If the laws are not ratified across the EU it means there is no universal consensus between EU nations. In that case it could be down to individual states to implement their own policy towards mixers.