About that whole 4th timeline consideration thing.
It was initially believed back before HH came out that there were only 2 timelines AT and CT after OoT split. Downfall just seemed silly [still does IMO, but whatever, it's official].
The way Downfall timeline exists causes problems IMO. Why aren't there multiple downfall timelines? Why is it specifically a branch off the events of OoT [that seems rather arbitrary].
Also CT and AT start to seem arbitrary points as well [less so than downfall]. They're created by time travel in OoT.... but OoT isn't the only game time travelling happens.
The earliest example of time travel [as far as the timeline is concerned] is the earliest game in the series, SS. Link travels through time multiple times in skyward sword in the desert. But ignoring the desert he also goes into the temple of time, as does Zelda and results in a timeline where both the goddess sword and master sword [the same sword] exist. But, that timeline that was abandoned can't be the one where BotW takes place because that timeline would have neither the goddess sword [to become the master sword] nor the master sword. So, okay, that's ruled out.
There's also OoA where link travels through time quite a bit. Shrug.... BotW is intentionally confusing with it's timeline placement.