Most likely there will be no Poland.
IMHO I disagree. Poland would more then likely meet the same fate as, say, Georgia or the Ukraine; namely, Poland would be turned into an autonomous Soviet republic ruled from Moscow. Thus Poland would be a federal state within the USSR, i.e. autonomous and not entirely independent.
The Provisional Polish Revolutionary Committee would give way, as I've stated already in my AH, to a Polish Communist Workers' Party which would administer Poland from Warsaw.
I do wonder what are the chances of German Communists seizing power in Weimar Republic if Poland is vassalised/absorbed by Soviet Russia.
Not impossible and, assuming a victory for the Soviets against Poland during the Soviet-Polish War, mostly probable IMHO. Red Army support would serve to shore up the communists' position across Germany, while cities already seized in the communists' uprising could be secured by Proletarian Hundreds and/or intervening Red Army forces.
The main POD for my AH is 1923, when Germany was in dire straits, facing hyperinflation, French occupation of the Ruhr, etc.
There really was a communist uprising in Hamburg, but it failed due to the planned nationwide insurrection being called off at the last minute by the KPD.
In my AH, the national uprising goes ahead which results in the seizure of Berlin, Hamburg and other German cities by KPD militants and the eventual intervention of the Red Army.