I don't know honestly but I too would have love to know what was going on behind the scenes of this series. This is the first work of the author that I read although I hear good things about about his previous work, Angel Densetsu, which been on my to read list so I'm not sure if this is just simply his style of concluding his series or what.
My previous thought was just an assumption since it felt like the series was dragging out with Priscilla then on a flip how quickly everything "wrapped up" in the ending, final chapter.