Did you miss the MTV-like music video of the Revolution, with Reed and Bryant holding hands and marching with the Proles while Internationale proudly plays on the soundtrack? The movie made it appear that Reed objected to his writings being tampered with, but as far as I remember, he was never shown to have fallen away from communism. He's buried in the Kremlin, after all.
I found the film to be totally pro-commie (and boring).
Also, Hollywood honored Beatty with Best Director as I recall. It probably almost didn't get made because it's not a commercial property. Remember-Hollywood is full of commies, but they are also capitalists when it comes to box-office.
That’s exactly why it almost didn’t get made. But Beatty’s goal was too make a film examining the roots of modern American radcialism in the early 20th century intellectual circles from where it sprang. How those people were hoodwinked by corrupt party bosses. The montage you describe is subjective. It’s from the point of view of Reed and Bryant who were smitten with the idea of revolution. Reed didn’t have much time to turn against the Soviet communists as he died before the Russian Civil War ended.