I think he's required to do so purely based on his jab at Lost. Having the
characters talk about going to get the scripts in the midst of Zpocalypse is foreshadowing that the storyline of his story are locked away in his safe and retrievable in case we need to. I bet the first 2 numbers to the safe are the chapter number/part number....but whats the rest of the combo Kc? We need to know....just in case.
This also creates quite a rendezvous point for We're Alive fans for when the zombies come. We'll all have plans in line with each other due to our shared interest for We're Alive...Naturally this would be the center of the real-life boulder in the event of Z-day