Scott's proven that most of his theory on FNAF is right. So he technically is.
Specifics: Scott stated that MatPat's theory on FNaF2, specifically, was almost completely spot-on. I don't believe he said much past that, other than he was disappointed by how everyone missed the mark on FNaF4, and, as such, he refused to open the box. I think he said that before
MatPat's "it was all a dream" video went up, thought, so who knows if he got it right then.