The AI in my game seems to be very good at avoiding revolutions up until 1500 turns into the game on Eternity. And only a few empires suffer from them after that. I'm playing on a huge (or giant) archipelago map. Many empires build 11-12 cities in Chiefdom (with city limits enabled. I can't remember if these still apply to the AI). So you might see no revolutions because the AI is now better at it than previous versions.