I am thinkin defeated timeline after Zelda II or before LoZ. I think the Koroks are the natural state of the kokiri, and they only show themselves in human form when hyrule is in power (for good relations.) I just played WWHD recently and the Great Deku Tree gave that impression this time I played it. Since the korok evolution relies on TGDT's magic, it could be possible he did the same in the defeated timeline as he did in AT.
Also remember that in Skyward Sword advanced technology implies the past.







