Everything changed. Everything. Especially with Season 2.
The timeline is alterable/revisable. The timeline was modified many times. There's one cabin. There's one Ash (less or more). There's one book. There are 5 versions (so far) of the very same timeline.
Most of the discrepancies between The Evil Dead and Evil Dead II, as well as between Evil Dead II and Army of Darkness, can be explained as the product of Ash's damaged brain and traumatized mind. First of all.
The Nexus, the time vortex, did the rest.
And so, the timeline changed. Thus, each ending is canon. The ED2 ending is canon, but not the way as you previously thought. The ARMY ending is canon. Even the "recaps" at the beginning of the sequels are obviously canon (Ash's twisted memory).
THE EVIL DEAD DEFINITIVE TIMELINE
THIS is my final word. THIS is my final scenario. And I'm finally proud of it.
Thanks for being here, have a good read.