I've never had it drop either, before the other day. I reset my valor rank (from 2000), something I've never done because I don't care much for the game's excruciatingly bad PvP, but I thought why not since it will reset anyway for the next season. The chaperone quest literally dropped to my inventory right after, when I went to orbit. I've seen other people say it dropped after a rank reset too. I'd give you mine if I could, I hate PvP quests, they can go f themselves.