I would say if German english (Denglish) would pick up French english Idiosyncracies and vice versa, so if the speech patterns aren't just a result of making mistakes in a foreign language, but if they are acquired by other speakers. The Euro-English article gives as an example of Euro-English "Planification" for "Planning" which seems to stem from french / spanish https://fr.wiktionary.org/wiki/planification . So if the Germans start using planification they would have learned it from the french/spanish Euro-english speakers (I never heard "Planifikation" in German although its actually a word in the dictionary, I looked it up). And that would mean that certain Euro-English features propagate throughout Europe and are more than just Denglish/Frenglish/Swenglish and more than just English-learners messing up vocab/grammar.

While we are talking about language, there definitely are also those folks who move abroad and after a few years when they return they have picked up peculiarities of the language of their host country. The daughter of a neighbor moved to Paris for example and after a few years she started to sound more french. Still spoke perfect german but with an accent. Similarly a coworker who is a US expat in Germany told me he caught himself using some Denglish constructions.