(BTW, accidentally post this on a wrong place. So that's the reason why I'm rewriting this)
Now, as we know by now (Don't read this if you don't want FNAF 4's ending). Fredbear did the Bite. But...Why is Foxy "Out of Order"?
I think the only reason Foxy would be "Out of Order", besides "DERE WAZ A BITE OF 123456789!!!!!"
Is that he was never finished, now. You maybe asking why he never was finished. Well, maybe the production of animatronics was already getting expensive. So, the company decided to cut one of the animatronics production. They probably chose Foxy, because he just wasn't popular with the kids. Only a few were halfy remodeled.
Why is he in a pizzeria, well. IDK, maybe they're planning to finish him when they got enough money. Which, never came to be...