Welcome to my favorite FNAF theories. My first theory is that FNAF 2 takes place before FNAF 1. That is because all the withered animatronics are broken so they were probably a work in progress. Also why Mangle is not a withered animatronic or in the first one is because the children at the pizzeria loved her so much, that they kept tearing her apart and the workers of the animatronics had to keep rebuilding her. My next theory is that Spring Trap is the phone guy because if you remember from night 4 in the first one, the phone guy dies at the end of his message. The phantom animatronics probably found him 30 years later and stuffed him in a messed up Bonnie suit. Also why I say messed up Bonnie is because if you look at a picture of Bonnie and Spring Trap, you may notice their ears are different (photos below).