I thought so too reading the first couple of pages of the decision, but in the judicial conclusion section, the jurisdictional issue is squarely resolved on the "targets German users" issue, which the court bases on 1) Partial translation of the website 2) The availability of German language works 3) The "anyone anywhere" language on the website 4) A disclaimer that people should check their local laws (implying in the opinion of the court that they knew non-US persons were accessing their material and intentionally targeting their offering to such people).

So yeah, while the language issue is only part of the judicial reasoning, is is indeed mentioned three times in the judicial conclusions. The court does not however appear to adopt plaintiff's theory on jurisdiction because some of the volunteers were German.

As such, I'm inclined to think that while the focus on the language issue is perhaps a bit overstated in their statement, it is definitely grounded in the opinion of the court.

As an aside though, I'm not convinced the court spent too much time considering the jurisdictional arguments here, which I think are probably the most important part of this case. Most of the analysis is concerned with whether the publisher plausibly alleged they own the copyright. I assume that is because that is usually the primary point of contention in copyright cases.