Comment by cyphar

There is a 2003 interview with Shigeru Miyamoto that suggests an "enormous" timeline document existed since at least 2002 and they took it into account when writing Wind Waker if not earlier games[1]:

> Shigeru Miyamoto: For every Zelda game we tell a new story, but we actually have an enormous document that explains how the game relates to the others, and bind them together. But to be honest, they are not that important to us. We care more about developing the game system… give the player new challenges for every chapter that is born.

So I don't think this is as clear cut as "a different group of people decades later make a timeline". The least charitable view might be that they never intended the unified timeline thing to became public and didn't consider it "lore", but I'm not sure I buy that either (since they talked about some details in other interviews, including the Victorious/Fallen Hero split most people object to).

[1]: https://www.nintendoforums.com/articles/40/super-play-magazi...