What’s historical revisionism is claiming the parade to celebrate the Nazis being pushed out of areas of Poland by the Soviets was a celebration of allyship, or claiming the “spheres of influence” were a real plan for dividing Europe and not a way for the Soviets to dissuade the Nazis from pressing too far while ramping up for war. Both the Soviets and the Nazis knew war was coming between them, the treaty was always on borrowed time and in no-way signaled long-term planning on either side, the Soviets wanted to stop the Nazi threat and the Nazis intended on wiping out the Soviets, “spheres of influence” be damned.

The Eastern Pact was the hopeful alliance between Poland and the Soviets (among others like Lithuania) against the Nazis, but this fell through due to France and Britain working against it, and Polish hatred of Russians. From the French ambassador to Poland at the time:

If, in reality, the most serious danger for Poland is Germany, “the Russian”, whatever the regime to which he is subject, always appears to the Poles as “enemy n° 1”: if the German remains an adversary, he is no less a European and a man of order; the Russian is, for the Pole, a barbarian, an Asian, a dissolving and corrupting element, with whom any contact would be perilous, any compromise fatal.

— Léon Noël, [17], 1938-06-31, Warsaw, p. 975-976

The UK and France regularly sabotaged talks of alliances with the Soviets and made their non-aggression pacts far earlier, doing far more trade and having far more Nazi synpathy among their publics and ruling class. Churchill is a famous fan of the Nazis until his hand was forced.