The Poles that I know in the USA are not very educated on Polish matters. They do not know how to speak the language, only understand the basics from their parents. They do not know how to read Polish at all. Yet, some were raised in a very strict Polish and Catholic upbringing, LoL, so the whole situation is odd. I would be an exception to this case – no strict religious or cultural upbringing, yet now I know more about my native language and culture that all my friends in Polonia USA. Irony.
The Russians that I know here, on the other hand, know Russian fluently, both in speaking and writing. And many have accents when speaking English. But this is probably because they came to the US later. Also many retain their traditions because they are Jews, aka a group of people that is the willing outsider, that assimilates as little as possible, no matter where it finds itself. The US is an unofficial haven for Jews from Eastern Europe in particular.
That said, I suspect that being an immigrant, or of a foreign culture, not int he USA is whole different experience. The USA and Poland have never had a conflict, while Poland and Germany have, as have Russia and Germany, so that makes a difference. Also, human civilization, overall, is becoming increasingly hedonistic, so young people just don't care about things like culture and learning languages as much as they used to. They'd rather get drunk. The Poles and Russians that I knew in the US were all-out party people. The Russians knew Russian, but not that much about what was going in Russia at the time.