That's interesting...some german has survived in Silesia after the expulsions? Awesome.
I was talking about Polish Silesians rather than German Silesians, but of course quite a lot of German Silesians survived the expulsions of 1946-47 and decided to leave for Germany later on after the expulsions based on the Potsdam agreement were long dead.
One reason was that the Polish authorities, particularly in Lower Silesia, at one time put a stop on German people leaving Silesia after they had realized that qualified workforce were leaving for Germany as well and there was a sudden shortage of specialists in coal mines, workshops and factories.
Those people left Lower Silesia in the 1950s or 1960s. But some of them have remained to this day in their Silesian Heimat. The number of original ethnic German people in Wrocław, for example, is estimated at about 2000 these days.
There are some in the Waldenburg (Wałbrzych) area, too. If you knew Polish, you could be able to listen to their interesting accounts on all those years between 1945 and circa 2000 and later on available on youtube. Born a few years before 1939, some of them they could remember how Lower Silesia looked like in German times. One lady is telling that the area around Waldenburg iss much cleaner and nicer in the present Polish times than it was before 1939 since coal mines and other industry stopped operating in that area. She recalls her pre-1939 Sunday excursions with her father in the vicinity of the village or the small town in which they lived. Another one remembers very well the Schloss Fürstenstein (Zamek Książ) from the time of the WW2 where she lived there as a daughter of a guardian. After the war she was making her living working for many years in the ticket office of the Fürstenstein (Książ) castle. Another one lady says she visits her family in Hamburg on a regular basis, but has rejected their offer to leave Poland and immigrate to Germany. She says there is no nicer land in the world than Lower Silesia, so sho would remain there to her death. The ladies also tell how they were reproached for talking German in the streets of their towns or villages in the times of the People's Republic of Poland (PRL) and add it all luckily ended after 1989.
All of them tell their stories in perfect Polish now. I could not hear the slightest difference in accent to the standard Polish, though some of them picked up the language characteristics for the Polish country people who settled in Lower Silesia after the war. I wonder if there exist those accounts with German subtitles for they would have been very interesting for you to hear.