I certainly made sure to mod my AIs to research cloaking before they researched Stellar Manipulations. It's just basic sense to cloak something as obviously dangerous as a planet killer or a star destroyer. And anyway, as others have noted, the AI is not smart enough to give them an escort, so the cloak is essential for AI operations. So far I've not had the misfortune to fall far enough behind an AI to get attacked with cloaked Stellar Manipulations before I was able to setup sensors to detect them.
