I don't really play many modern games, and the ones I do I usually buy the DLC when I get bored with the game, good examples are New Super Mario 2 and Mario Golf. I don't have to worry about it disappearing though because the DLC is saved on my 3DS. It's a good idea to have DLC if they add things later that they didn't have time to make by the release date, they could just stop and not give you anything else, but it's a nice option and fans probably appreciate it. It does take more work if this is the case, so they would have to make money on it because they have to pay their employees. Of course it's bull if they have everything done and don't give it to you on release though.