Unless you're 126 years old, that excuse doesn't really hold up. Plenty of immigrants came from Italy, Poland, and Russia more recently than your mentioned time, but you don't hear Press 3 for Italian too often.

Well... they weren't immigrants, they were annexed. Why should they speak English?

They didn't have to. But they also shouldn't expect the annexing government or populace to accommodate them.

Their country lost the war, lost the territory, and those that stayed and chose to take American citizenship should've learned English, the (de facto) language of the country they chose to join.

People still speak German in South Tyrol even though it's part of Italy since 1919.