They probably talked to him during the Iwata Asks that covered the forest. I remember one of the guys saying the last time you go to the forest is unbelievable.
http://iwataasks.nintendo.com/interviews/#/wii/zelda-skyward-sword/1/4
Seems Hiramuki was the one that said it.
Ito: Yes. And personally, I really like the character Fi.
Iwata:Fi is a character who goes with Link on his adventure and navigates.
Ito: That's right. We call the system Fi Captioning. For example, if you target various characters and enemies and call forth Fi, she will talk about them. And what she says is really funny. (laughs)
Iwata: Sometimes you learn things you wouldn't otherwise.
O_O