I think the original point is that Poles or Germans of Polish descent who survived the war have been forcefully Germanized - as in, refused the right to organize Polish schools etc. not in the modern days, but in the post war era (45-89).
There is a big group of these people (e.g. in Ruhr area) but it's really hard for me to tell (and I'm a Polish migrant living in Germany myself) if that was the case, or it was the idea that Poles/Germans of Polish descent after the war were afraid of ethnical Germans and as a result, repressed the manifest of national identity/ethnicity. It definitely was (and still is) the case for Jewish survivors of the 1939-1945 regime, but the anti-Jewish and anti-Polish sentiments didn't end from day to day and it's extremely hard to narrow down what was the cause of it.
>The position of the German government is that after the German territorial losses after World War II, the current Polish minority has no century-old roots in the remaining German territory, because Germany lost all the territories where people of German and Polish ethnicity overlapped. Since they are therefore only recent immigrants, they do not fulfill the requirements of a national minority according to the Framework Convention for the Protection of National Minorities and the Treaty of Good Neighbourship. Being German citizens, they still retain all civil and political rights every German citizen possesses, and therefore can voice their will in the political system.[10]