Up to the mid 50's, yes - but afterwards?
The Soviets had the Poles to do their dirty work for them after that. Why get involved and inflame the locals when the locals will do the hard work for you?
My father's friend a born Varsovian who's family came from there from before the war ever, told me how he was in the army in the early 70s and Soviet soldiers tapped into Polish telephone/communications lines and listed in on peoples conversations, which made him furious. His commander said 'they can do whatever they want, don't interfere there will be consequences'.
It wasn't, not in the strict meaning of the word. Occupation is when the authorities are totally under the control of another state
Polish communists wouldn't have stayed in power. Even Gomulka as a communist who wanted a bit more freedom was fully aware of this.