Well it's generally a good idea to ask a fellow traveller when you hear an announcement you don't understand. Especially if it doesn't use words you've commonly heard before. And maybe tell them instead of having Schadenfreude?

Which is what happened next.

The point was that even in international trains inside Germany, announcements related to trains problems are only done in German.

I speak it fluently, including some variations, however most travellers do not.

I also remember there used to be ticket machines in NRW only in German, about 20 years ago.