So they were not liberated and I stand by that statement.
No, it's not "my perception", but historic facts, which has become all too fashionable to twist and forget.
Using your twisted kind of logic, Soviet Union was a free country before 1941, so it didn't liberate itself from Nazi German occupation.
Situation changes, and, I re-quote:
Nope, definitely nothing for Poland to be liberated from. [/sarcasm] I am sorry millions of Soviet soldiers lost their lives, for their sacrifice to be treated with such arrogance.
EDIT:
Whether Poland was free or not before WWII is a moot point. War was coming to Poland whether it wanted it or not. There were 3 possible outcomes:
1. Soviet Union could have ignored what was happening in the West and let Germany take all of Poland. This would have given Germany a signal that Soviet Union was weak and could be attacked. As USSR was engaged with Japan in the East, it would not be able to fight on two fronts and would have lost. Result for Poland - it would not exist today.
2. Soviet Union could have challenged Germany, declaring it war, when it became apparent that Germany was going to expand Eastwards. It would have been suicidal for USSR. As USSR was engaged with Japan in the East, it would not be able to fight on two fronts and would have lost. Result for Poland - it would not exist today. Incidentally, this is the scenario that was favoured by Washington and London, which were in negotiations with Germany about letting it fight on one front - Eastwards. Result for Poland - it would not exist today.
3. USSR could have tried to delay the start of the war as much as possible and conclude the war with Germany's ally, Japan in Mongolia. The negotiations should give Germany a feeling that it gains something (a part of Poland), while at the same time give it an impression that USSR is too strong to be attacked right away. This is the scenario that happened. Molotov-Ribbentorp pact achieved just that. USSR beat Japanese and moved several armies to the Western positions. Result for Poland - it had a fighting chance to continue its existence after the war was over.