The same guy that first sent messages about the current diseases going around sent code messages about the sleeper, there was also Caydes map that for some time was suggested to have something to do with the sleeper. Bungie did plenty to build sleeper hype and it turned out to be a huge disappointment, as will this probably! I really hope there is more to it, I'd love it bungie put these crazy puzzles into the game, I also seriously doubt they have.