For the last 4-5 months (on and off) I've been trying to get the No Backup Plans for my Titan, I would wait until exotic arms were dropping from the Legendary and Master Lost Sectors and then run them multiple times throughout the day. I have never gotten the No Backup Plans and I thought that the first exotic to drop would be the special exotic that was only acquirable through the lost sectors before I would start getting random exotic arms, however I keep getting these random exotic arms, as well as occasional alternate exotic armors.