You understand that it was not possible to download an expansion for a ps1 game, right. Nor was it possible to download additional characters in pac man? Nor was it possible to download additional map packs for doom. You think if the infrastructure was there for those games, that they wouldn't have been downloads rather than things you had to go into a store for?
If you can't understand how an expansion pack, and a DLC (you know what DLC stands for, right?), is in essence the same thing, then you should probably spend less time working on trying to sound smart on a karate forum, and more time working on that common sense. In this day and age, expansion packs are DLC.
And yes, DLC are expansions. They may not be titled expansions, but they are. You know what expansion means, right?