Eh, I dunno that I’d actually characterize him as a liberal so much as him being an authoritarian that just pushed whatever happened to serve him at any point. Kinda in the same vein of fascists not having any economic ideology, just whatever serves their ideal of the state at any given moment. So yeah, I certainly agree with your sentiment that Stalin certainly was not a communist, but more because he only cared about gaining/maintaining power rather than actually subscribing to any economic theory.