So, each Adventure has its hint:
Adventure 1: bottom left, golden sands + the compass.
Adventure 2: bottom right, vessel.
Adventure 3: We know adventure 3 is called "Shrouded deep2 (or something like that, my game is in Italian) and top left of the title screen we got a meg jaw with what looks to be the killer whale inside, which we can safely assume is an Adventure 3 hints.
Now, logically I'd assume the hints are going counterclockwise and so top left is Adventure 4 hint: a damaged flag with 2 swords and a chalice, the chalice is also on top of the map, at the center. (the mask on the left is a clear hint to the PL Voyage instead, as in the trailers we saw the Pirate Lord holding it).
So is the chalice the only hint we got for Adventure 4? I don't think so: take a closer look at the map in the title screen.
The Devil's Roar is missing, we know that before year 1 the Devil's Roar was still inside the Shroud, but we also know that in some cases the opposite happened and some island actually got engulfed by the shroud, like Tribute's Peak.
Basically I think that that map is a memory summoned from the past too, at the time the Devil's Roar was still within the Shroud, but 3 new very big islands can be seen on top left, top right and bottom right of the map, one per sea (excluding the Devil's Roar).
Could it be that with Adventure 4 we're gonna see 3 new islands coming out of the Shroud? What else could those marks be?
PS: unfortunately, as stated below by others, i was wrong about the islands, the map on the title screen always had those 3 islands at each corner but bottom left. :(
