My previous blog post didn't really seem as good as I intended. This post offers a better explanation of my FNAF World theory. (My The End RP actually uses this theory, btw)
You see, after the events of FNAF3, we have the animatronics from the Thank You teaser, all lined up in one. A new buiseness begins, with all the animatronics coexisting in one big attraction. Soon, the animatronics are updated to be more kid friendly, and technology to recreate the missing Shadows, phantoms, and Fredbear arrives, as Balloon Girl is added, making Fredbear become a part as well. This would happen likely around 2026.. This is the most likely backstory of FNAF World, before evil comes within, and the events of FNAF World begin.
Another possibility is that a new location uses these kid-friendly models, which I used for my roleplay, but that was simply to add more story, and it is possible, but not exactly my theory anymore.