I'm not so sure about the "KG is RAURU! Rejoice!" theory.
Yes, Kaepora Gaebora is the name of the owl that assists you throughout your quests in Hyrule and Termina.

There are two characters in Majora's Mask that have that name. One is Kaepora, One is Gaebora. They're the two smiths that work up in the Mountain Village area.