I don't particularly care for Pixar movies (I prefer traditional animation over the CGI stuff that Pixar does), so I haven't seen nearly enough of them to know if that guy is full of it or not. It wouldn't surprise me if it's true though, it's not the first time that something like that has been done.
But her love for Sully is, after all, the crux of the entire Pixar universe. The love of different people of different ages and even different species finding ways to live on Earth without destroying it because of a lust for energy. And that is the Pixar Theory.