Of course Civ 2 had to be perfect on delivery, because there was no online patching back then. Modern tech had made it easier to release unfinished games to test the waters and patch them up later. DLC also didn't exist back then.
Civ 2 actually had a bunch of official and third party expansions, but they weren't as consequential, and it was a complete game without them in a way that its successors were not.
I do recall a mod or scenario where you basically replayed the entire history of Rome in surprising detail. Tons of scripted events.
And obviously the Web was very much up and coming when Civ 2 was released, but I don't think releasing a game through downloads and updating them through the internet was really much of a thing yet when it was first released. As far as I know, everybody ran it from the CD-ROM. Also because that's how you got the awesome advisors (still the best).
