This question doesn't make any sense. It's also not really a business or economics question.
In 1945, Poland became communist because the Soviet Union "liberated" it from Nazi Germany but actually just annexed it. Nazi Germany was a socialist country with a tyrannical leader and genocidal policies, not a feudal society. One of the defining features of of feudalism is a group of people who belong to the land on which they live. The owner of the land also owns the people, called serfs, but only by default. If someone else claims the land, they claim the people, too, just as they would claim the plants and soil and water. Therefore, the people cannot be relocated. But we know that the Nazis did plenty of relocating. That's not feudalism.
Serfdom in Poland was abolished very late in history compared to other cultures. It occurred gradually in the various countries that had partitioned Poland, so the abolition was not complete until the late nineteenth century. Therefore, there were cultural elements of it that were still present in the twentieth century. But it is a stretch to say that cultural remnants in a fractured former nation equate to a form of government or dominant political ideology, feudalism or otherwise.