Okay this is a take that I was not expecting and haven't heard before but makes sense if you think about it for a while.  While I was watching there was once other instence of time travel in media that came to mind and that was from the 90's X-Men cartoon and there was a series of episodes called Beyond Good and Evil and in the episodes Apocalypse takes Cables time travel device and travels back in time to have it so he rules the world and since this was his first instance of time traveling the Axis of Time brings him to there and it is essentially a central hub where time travelers can go before going out to their destination that they were intended to go in the first place when they first time traveled.  So with your theory that Link going to the Temple and time and sleeping there for 7 years it is like without Link for those 7 years Ganon took over and you have the Adult Timeline.  Well what if Link never woke up and you could possibly have the Fallen Hero timeline right there until the start of LTTP where he wakes up in a brand new world which is much different from OOT.  Interesting to think about.

I always thought the time split made sense for some of the reasons laid out in the timeline.  In OoT, you have to go back to the past at least once.  That, to me, was the the actual time travel: when Link sends his consciousness back to the child timeline to get the Song of Storms (and the other things).  I took the sleeping literally in that his body is just asleep in the Temple of Time, where Gannon can take the Triforce from his body.  When Link goes BACK. . .TO THE FUTURE! in order to defeat Gannon, he's now in a different future.  The old future was abandoned, and the hero fell.

I really liked the video. It definitely put out some info I hadn't fully considered before, and I think you do an excellent job explaining things.