EU laws come in a couple of variants. The most common is a directive which is basically "Your country needs to pass a law to achieve X, Y, Z", and this is where you get larger country to country differences in interpretation. The GDPR is instead a regulation. That means it's literally the same law (and theoretically, the same standards) that applies EU wide. So the US equivalent would be a court in Texas finding something to be illegal under a federal law. What does that mean for the same action in california? It's probably illegal there too, but it could still be tested if someone wanted to try their luck.

So that means the current status is that's precedent a court in another EU country would strongly consider but technically could come to a different decision on and in either case the losing party has the option of appealing to the EU level.