@bazookaxp: This is assuming that the servers still exist in the same capacity that they did when whatever game in question launched. It seems naive to believe that anyone would dedicate any amount of server capabilities to older games for extended periods of time.
Also @alexglass, there really isn't such as thing as an "addition" in the gaming world. Once someone sees the game with the "extra" effects on, that becomes the baseline for what they expect the game to look like. So when you are not connected to the server and your game looks less then what it does when connected, you get the sense that the game is incomplete and missing elements, rather then the game adding something.
They don't just dedicate to the specific game it is dynamic and they can host any game at any time.