Welcome to D&D, spaceships and interseller/interdimensional empires have been a thing since Gary & Dave wrote them. That's the entire backstory to the Illithids. And the Gith (both).
And they've been significant players in The Realms since Ed (really nice guy) started writing it.
Even in traditional CRPGs they already had their spotlight in Planescape: Torment through your companion Dak'kon.
