The Old Man on the Great Plateau — who guides Link through the tutorial area, provides the Paraglider, and speaks in gentle riddles about the land below — is not introduced by name. He says only that he has lived on the Plateau for a very long time and knows it well. Most players accept this and move on.
He is King Rhoam Bosphoramus Hyrule — the last king of Hyrule, who has been haunting the Plateau as a spirit since the Calamity took his life a hundred years ago. His true identity is revealed in a memory sequence unlocked after completing all four shrines on the Plateau. He then removes his disguise and delivers a full account of what happened to Hyrule.
The disguise’s purpose is explained in his final speech: he did not reveal himself immediately because he needed to know whether Link was truly ready before committing Hyrule’s last hope to him. The entire tutorial is a test conducted by the king whose kingdom Link is about to attempt to restore.
On replay, the Old Man’s dialogue contains multiple references to Hyrule’s history that only make sense if you know he is the King. He refers to himself as someone who ‘could have done more’ with careful weight. His eagerness to hear about Hyrule Castle reads as grief, not curiosity. The disguise is emotionally coherent with who he actually is.

This is why I always check every corner. You never know what’s been left for the observant player.
The environmental storytelling in this game is on another level. Thanks for documenting it so clearly.