Look at this picture. To the left is the world map for Super Mystery Dungeon, and to the right is the world map for MD1. Could this be not a brand new game, but a remake of MD1? If I remember correctly, it took a bit of time for them to make it clear that Explorers of the Sky was an enhanced version of Time/Darkness as opposed to a sequel. Fingers crossed that it's just a coincidence and nothing else. But the name "Super Mystery Dungeon" kinda looks suspicious now with that knowledge in mind.
That said, I wouldn't say all is lost if it IS a remake. So if that's what happens, at least I hope they keep some of the improvements MD2 brought, like more bag space, no Friend Areas and the ability to recruit Pokémon even when you have a full party. Though I wouldn't say no to the infinite inventory space MD1 had, either.