I don’t think that had much to do with it. There was a lot of conflicting propaganda at the time and conditions in Soviet Russia in the late 1920s were good. Regardless, communists weren’t so easily persuaded.

The exodus was partly a reaction to poor conditions in Russia and the fact that Stalin, as opposed to Lenin before him, did not believe in pursuing worldwide revolutions. Stalin withdrew efforts to support communist parties worldwide.

But the main thing that encouraged withdrawal from the communist party was The New Deal.