Welp... it looks like OS X is about to discover tiling window management lite. ;)
Amethyst (an automatic or dynamic tiling window manager), on the other hand, automatically arranges windows according to predefined tiled layouts (like XMonad, Awesome, etc.).
What I'm trying to explain might become more clear if you watch [0], wherein you can see that all windows on the (virtual) desktop are adjusted in size and position in response to opening or closing other windows.
As for "Split View", it looks more like a simple two-window extension of the existing full screen functionality to me.