Traditionally in games set up this way, it means that those raids are no longer useful and the only reason toplay them is collectors looking for things to vault, or to break up the monotony and go on a blast from the past. Wow for example is littered with a decades worth of raids, last i played damn near all except 2 were useless. If your not used to the idea of zones becoming useless that you loved, you will. Its the nature of the beast.