According to the description for Eyes of the Universe, it does not reveal all homeworlds. Instead, it reveals the homeworlds of all hyperdrive-capable civilizations. This may indicate that a tech needs to be researched before they are considered to be hyperdrive-capable. The problem with this is that everyone starts with the Engineering tech, which allows the hyperdrive, so all races should be hyper-drive capable at the start of the game.
Maybe the game expects a different tech to be researched before they are revealed, or maybe a ship with a hyperdrive needs to be built before they are revealed, or maybe it is something else, or maybe it really is a bug like you think. That's a lot of maybes.
It has bothered me, but whenever I manage to build it, all the races are eventually revealed. Maybe one of the devs will explain how it actually works.