I purchased Glaciv IV, the expansion pass, and Supernova upgrade on Epic. I just used the Steam key transfer service. On Steam, I now own only the base Galciv IV game. I do not own the Supernova upgrade, nor the expansion pack, nor the DLC.
Was this what was intended with the transfer?
Looking at Steam, it is difficult to tell what version of GalCiv IV I have. In my library there is no mention of Supernova. On the Steam store page it looks like only the base game is for sale. When you go to purchase the game, it does show the supernova edition.