In OOX, Zelda sensed the Oracles, and perhaps Hyrule, were in danger. Could that have been the motivation for the AoL BS king (the prince's father) to split the triforce?
Oh, and the reason Hyrule would have changed so much in Link's absense is because Ganon, well, destroyed it. For Hyrule to get so badly wrecked in The Legend of Zelda, Link surely had to be absent for some time and he had no tools when he arrived; I use this as explaining that his long absense was his attempt at getting back to Hyrule after Link's Awakening, when he lost his tools.
Ganon in Link's nightmare can also be said to not only reference A Link to the Past, but foreshadow his return that could began when Link was still in the dream world.
