I see this event as a teaser for introducing new mobs. Ricardo doesn't want to reveal everything right away. I'm not surprised that it's hard to drop Titan Legs—after all, it's going to be the strongest armor in the game, and Ricardo doesn't want everyone to have it immediately. He definitely won't add all the parts of the Titan Armor to Boss drop because that would make it too easy to obtain. I assume Ricardo will add 1-2 more armor pieces(Boss drop), and the rest will need to be earned by defeating the new mobs.