In 1939, the “ideal scenario” assumed by the UK authorities at the beginning of the war between Germany and the USSR was the partition of Poland, which was sacrificed by the UK to inspire a conflict between Stalin and Hitler. In this situation, the UK would have been able to present itself as a peace-making force, increasing its influence in Europe. Although, this “UK schedule of war” was thwarted by Hitler, who forced Stalin to sign the Molotov-Ribbentrop Pact and attacked France instead of the USSR.
The refusal of Poland to allow Soviet troops to pass through its territory in 1939 was a mistake by the Polish authorities. The USSR could not wait until the German troops appeared on the Soviet borders and started a war against the Soviet Union from the surroundings of Minsk. Thus, if Poland realised a rational policy (based on its national interests), it would have been treated differently by the Soviet Union.
This message is part of the Kremlin’s policy of historical revisionism and an attempt to portray Russia's role in World War II as not aggressive - see other examples referring to Ribbentrop-Molotov pact here, here and here. The accusation that the Polish authorities provoked the Soviet army's intervention in Poland in September 1939 by their refusal to allow Soviet troops to enter their territory is a clear historical manipulation. In terms of the Molotov-Ribbentrop Pact, it is a proven historical fact that it contained the Secret Supplementary Protocol, which assumed the division of Poland and other Eastern European countries between the USSR and Germany. Thus, the signing of the Molotov-Ribbentrop Pact directly caused the German and Soviet military aggression against Poland in September 1939, which resulted in its complete occupation by Germany and the USSR. See similar examples of the Russian historical revisionism concerning Poland here and here.