The two "shadow" boxes in cachalote picture have the rough dimensions 1x4x7 and 1.5x6x8 - do these conform to any of the already known releases?
The 4444 cannon ship would seem a much more likely candidate for one of these two limited edition sets - though the box is much deeper. That may be due to the angle of viewing in the picture, or it may be those boxes are just for the picture and aren't the real boxes.
The 4444 set would fit the tricorne hat theory, though the klicky who wears the tricorne hat in that set doesn't have the same hair as the shadow figure.