One theory I heard is that the kid in 4 is the son of purple guy who also had a daughter as in the house the protaganist of 4 lives in there is a room for a little girl in the same house.
Hmm...it seems a bit far fetched to be fair. Like why would there be a house connected to a animatronics location?
Yeah, I agree. One theory said the house is part of the experiment by the Purple Guy to torture kids.
that is something to think about