Why a new timeline has to be created? Honestly...
X1 and X2 have hinted Charles´and Erik´s knowledge about Wolverine (mostly X2, with Magneto telling Charles: "you haven´t told him about his past, have you?")... and Charles wanting Logan to let his mind "recover" by itself.
So... my assumption is... Logan DO awake on a corrected 2023 without the apocalyptic future, BUT not necessarily cancels XM

W, X1, X2 and X3.
Upon Wolverine´s request, Charles can erase from his memory the incidents from DOFP, and just telling him something like: "I´ll come to you guys in time"... and wake Logan back on his place, where he was before the mind swap with his future self took place (As he did with Moira on FC).
Now, about fixing X3 "failures"...
People, Scott never died on-screen.
He could very well still be in a comma on Alkali Lake or nearby... Maybe picked up by someone (Nathaniel Essex, maybe?!). Last we know, Jean cancelled his powers, so maybe he is still on induced comma or something.
As for Jean... well... she is the Phoenix... also... was her body buried? What if her body is still on comma on the mansion, only known to a few? Jean´s conscience hasn´t trascended to a different plane as seen on The Wolverine, where she mentions to Logan: "You put me in here"... She seems to be dawdling on an astral limbo.
So for the corrected 2023, we can have the cameos of Scott and Jean, and leave people like: WTF? How come? The movie doesn´t really need to explain that. It could be further explored on a future OT movie.
Well anyway, that is my thought.