The current rebel system is from the TEC research ability RESEARCHSUBJECT_REBELLION. Even if this ability is unchanged and stays as a research system for TEC players only, the current AI can't handle it properly.

I've found that whenever a TEC player researches this and Rebel ships start appearing at various planets, the current AI will throw an absolute fit.  Whenever rebel ships attack one of its planets, the AI will drop whatever its doing (even in the middle of it attacking something else) and send all its ships to whichever of its planets is being attacked by a whopping few rebel ships.  This makes even the hardest AI a complete pushover. 

What I would like to see is for the Rebellion AI to simply fortify all its planets or keep a reserve force just for Rebel attacks.  I don't want it to keep throwing a fit and sending everything it has at a few Rebel attackers.