So im playing as Austria and I haven't had a single rebellion before 1880 where only 2 brigades of Jacobin Rebels revolted. The Communists haven't popped up yet. So has Paradox totally destroyed the rebels now? =P
Trust me, no matter what, Rebels will appear if they don't sporadically rebel. Once had 35 years without rebels then 1.14 million communists decided it was the right time.
The more I play, the less I understand the rebellion mechanics. With Russia, I never managed to build up any militancy even when I tried hard, but had frequent full scale revolts in all 150 or so provinces. With Germany, I built up mil to 6+ many times without ever seeing a rebel.