They can. But they should also not be assholes with everybody else. And no not just local trains, I got information in English exactly zero times when there were huge delays on international trains. And it happened 2 times from 3 when I tried to cross Germany by train. And Germans (and Austrians btw) are terrible with this, even compared to others. The German site at my multinational company at the time was the only site on Earth which had to introduce an internal regulation about mandatory English, because they just switched to German all the time even when there were people on the call from different countries. I’m living now in Wien, and they are terrible with this even in friendly environments.

YMMV. I worked in three different German startups in Berlin and I almost never heard anybody speaking German in the company, even though more than half of the people were from Germany. Maybe it's different in bigger companies, or outside Berlin?