We can't know for certain but what we do know is that Adolf Hitler was not a stupid man. The other countries he had bullied into giving up territory were all smaller and did not have military up to the level of Poland's. What people don't usually take into account is that Poland did actually have a respectable military force by the beginning of WWII in 1939. The entente had already declared their support for Polish independence and were still trying to avoid a war with Germany by that point. As we can see with Austria, Czechoslovakia and Lithuania, Hitler kept taking land because no other countries were willing to stop him. At this point, I can't TELL you what Hitler expected from the Poles. However, I and you and anyone else are all allowed to voice their thoughts on this subject or any subject in history. History is fluid and the answer is not always straight forward both when we have sources to inspect and when we don't have anything to go off.

I'm extremely sorry if my answer didn't help. I thought I should at least try to answer your question where others can not.