The opposite actually. When you upgrade your regional MIC, which is the type of building your talkign about, it says how many units of slaves will revolt. This number of slaves is the amount of units of slaves (a weak but numerous unit) that will become the force under your command should your settlement be taken, and then revolt against the invaders back to your side. This also happens when a city you may have just captured revolts, and you havent destroyed their Regional MIC; slave units appear, usually with an annoying 3 gold chevrons and the third armour and weapon upgrades.