What if FNAF4 will take place in a movie set?
Ok, I know this is a stretch, but here is my theory.
A movie maker decides to tell his version of the events in the pizzerias, from the bite of 87 to the horror attraction burning down. It will be like one of those horror movies that are based on true stories or something like that. This could mean that the design of the animatronics, in case they built models of them, is going to look exaggerated to give the viewers more of a fright.
During the production of the movie you, as a night guard, will have to, what else do your job and make sure no one breaks in and yadda yadda, until the animatroni