I think for a new player it would be great to have access to older roadmaps that have the stories added into them.
Same deal for veteran players to be able to replay them and get to enjoy the story again if they enjoyed it the first time.
To make the map a little more user friendly you could add a second/third/fourth/etc page (similar to the world map) to the roadmap. Maybe even theme them a bit differently so the missions with story would actually coincide with the general area on their respective map.
Edit: I also think the original prizes should be kept, even the collectible prizes. At the same time bringing back those collections.
Of course, holiday specific maps make sense to keep hidden until the corresponding holiday rolls around.