Occult is not the social Ability for spirits because this puts an Eclipse or a Zenith at a disadvantage in the place where they should be really good. It also messes with normal depictions of the Exalted as a whole. In a game where your personal charisma and magnetism can push your persuasive ability so high that you can dissuade a Deathlord, or sing a song that breaks the heart of a Yozi, it makes no sense to gate that behind Occult, which measures neither persuasion nor musical talent.
You can roll Occult to know things about the spirit world, to identify thaumaturgy rituals, to figure out how a sorcerous working "works" (may require Essence sight Charms in some instances). Just like Larceny can be used to establish how much you know about the criminal element or the boryokudan or underground trafficking. You can technically read and know about those things by way of Lore, but Larceny accounts for hands on experience or first hand knowledge. Think of Occult in a similar fashion.
Hope that helps.