Very little to see here. This is the support lifecycle for Windows 10 Mobile version 1511, the shipping version of the OS. The version is 10.0.1 something. It is very likely that Redstone will update the versions to 10.1 and the support lifecycle will reset.
If Microsoft is able to get everyone onto required updates then support lifecycles will have little meaning since everyone will be upgraded to a new version inside of a two year window, changing their support dates.
A huge step could be made in this process if MS can help push non-traditional phone OEMs like Acer and others to the forefront by encouraging universal unlocked phones that can work everywhere at a reasonable price. The Jade Primo, for instance, could come in at under $400 with a Continuum dock, keyboard, and mouse while touting some nice flagship specs (the only thing subpar is the 1080p screen as opposed to QHD). Others can follow that model and just make the phone as a PC model that has use beyond being a phone.