To make sure we're all on the same page about this quote...
The quote was said in late 2008, but by the context, he's talking about at the time of the game's development. He doesn't given any indication that the intent has changed since then though.
I've been informed that the last line (which...
Likely, but I wouldn't say it's definite. The intro of Majora's Mask does say that the story of the Hero of Time was passed down amongst the Royal Family (on the child timeline), but Wind Waker actually shows a room full of stained-glass windows dedicated to the Sages. Aonuma's quote seems to...