I assume they were deliberately removed. The maps were available in multiplayer up to at least version 1.0.20 (didn't install 1.0.27) but are not in 1.0.33, and several people have brought up the issue of starting out fresh on a map where the AI has 75% control, all units available and fully upgraded. Presumably when the GOG version is updated tomorrow the story maps will also be removed from multiplayer.
