Just because it clearly states
if does not necessarily mean that it's going to be a "what if" scenario. Like some of you mentioned, it also says
if for the defeating Ganon timelines.
The Hyrule Historia quote posted above ^:
"In the beginning of the creation of heaven and earth, there was the Triforce, and after "Ocarina of Time" *it* [the chronology] splits into 3 axes. It is between if Link wins and if he's defeated; if Link wins he is sent to the child era and disappears from the adult era."
Notice that the CT and the AT are slightly explained in this quote and the DT hasn't been explained at all? You can immediately assume that it's just plain and simple, a "what if" scenario. However there is still a whole lot to add on to it. With the release of future games, the Hyrule Historia could be updated, which could clarify most things. Or maybe a new game could take place in the events before
ALttP featuring a "secret legend". Who knows, but if I were to choose, I would go against this "what if" scenario, Nintendo is not that lazy/stupid.
The timeline is not completed, and is not going to be for a long time.