So funny development. You are correct in that after the end of that one story arch, the next brought me back to the Order of Whispers. My next mission was to go and meet the Ogres with my Order contact. Upon entering the instance, not only was my Order contact, Leftpaw there, but as was the Sylvari Priory contact from the previous missions, Sieran. They were standing on top of each other, both with the quest starburst above their heads. If I talk to Leftpaw, I get the dialog with him, however with any of the automatic cutscenes it remained with Sieran. Continuing on, this repeated until the Battle of Claw Island, where once again it was all Priory. Leftpaw stayed on the dock while Sieran accompanied me throughout the mission. The end of the mission involved the head of the Priory, and the next mission is clearly Priory as well. This is definitely not right, so for the time being I will keep the ticket open and update it accordingly. I know I have no chance of seeing the Order of Whispers story on this character any longer, and that's ok, but the result is most certainly a bug.