Just because it is the artstyle it doesn't mean he is a kid.
The Oracle games were not developed with the current timeline in mind.
That happened later with Hyrule Historia.
Princess Zelda doesn't even causally greet Link.
It is like they have never met before.
Anyways, a good hack can change anything.
Allow me a little alteration:
Din: "So you are the Hero of Hyrule and Master of the Triforce... How I know it is you? Your Triforce marking on the back of your hand is the prove. Only those who have proven themselves worthy of Wisdom, Power and Courage carry the sacred symbol, which indicates that they can use the Triforce. This person is you Link."
Onox: "This is the young man who defeated my lord and master?! Impossible... That a worm like you could be the legendary hero... Laughable... If you were him, I would have atleast expected a formidable opponent. Anyway... You along with all the other mortals shall witness the destruction of this land. Enjoy your last days... They will be your last. Fufufu..."