Though not always a relaiable source, Wikipedia says something different:
Read again what you have posted:
Another problem that Polish authorities were faced with was the disposition of the so-called "Germanized Poles" or "autochthons". Of close to three million residents of Masuria (Masurs), Pomerania (Kashubians) and Upper Silesia (Silesians) of Slavic descent, many did not identify with Polish nationality, were either bilingual or spoke German or Germanized dialects only.[87] Large numbers of these had registered with the German Deutsche Volksliste during the war. While those who had signed Volksliste category "I" were expelled, the Polish government aimed to retain as many "autochthons" as possible, as they were needed both for economic reasons and also for propaganda purposes, as their presence on former German soil was used to indicate an intrinsic "Polishness" character of the area and justify its incorporation into the Polish state as "recovered territories".[87] "Verification" and "national rehabilitation" processes were set up to reveal a "dormant Polishness" and to determine which were redeemable as Polish citizens, few were actually expelled.[87] "Autochthons" not only disliked the subjective and often arbitrary verification process, but they also faced discrimination even once verified. Polish settlers coveted autochthon property, and they resented and distrusted the verified autochthons. Many autochthons fled to occupied Germany in despair at their treatment, although the situation in Germany was little better. As one Silesian wrote, "In Poland, I'm a German. In Germany, a Pole. Perhaps they should create a state for us on the moon. There we might finally feel at home".[88]
The verification procedure varied in different territories and was changed several times. Initially, the applicants had to prove their past membership in a Polish minority organization of the German Reich, and in addition needed a warrant where three Polish locals testified their Polishness.[89] In April 1945, the Upper Silesian voivode declared the fulfillment of only one of these requirements to be sufficient.[89] In the areas like Lower Silesia and Pomerania, where the Polish authorities suspected only Germans, verification was handled much more strictly than in the former German-Polish borderlands.[9] Of the 1,104,134 "verified autochtones" in the census of 1950, close to 900,000 were natives of Upper Silesia and Masuria.[9]
Also current PM of poland is Kashubian.