Well, as with Art evolution, these character design changes were inevitable. Not only does

seem to have drawn his own versions of the FNAF 1 FNIA animatronics, but his art style has evolved a bit to look a bit more like anime. With that said, I decided to redesign these babes to reflect Mairusu's designs more closely while still keeping to some elements of my old designs and having their own flare overall. And I kinda like how they came out.
So now, I think "Hey! Why just redesign them when I can make said redesigns a part of the story?!"
So in the year 2056, all was well and good. New models and animatronics were slowly being introduced to the roster, profits were coming in and the girls were hard at work doing what they do best. However, with time their bodies began to show signs of wear and tear and thus weren't getting as many hits as their owners wanted. With that, they decided to try and create new bodies for these girls, updating their designs to match the newer animatronics that were available at the time. At first they considered making all new bodies for the girls and transferring their A.I into them, but they ultimately decided to just fix up the old bodies and polish up their code a bit, which was considered a relatively cheaper solution. And that is what they did. They also decided to give them clothes for when they are commissioned by somewhat more conservative clients or for birthday parties when the Minis were preoccupied.
FNAF (c) Scott Cawthon
FNIA is a parody by

Contemporary Animatronics 1.0 -
fav.me/dbpzelz
Mini Animatronics - fav.me/dbpzezm
Extra Animatronics - fav.me/dbpzf93
Classic Animatronics - fav.me/dbpzfpu
Withered Animatronics - fav.me/dbpzgon
Golden Animatronics - fav.me/dbpzh3p