Narnia isn't static. There's a thread throughout it of belief/unbelief, the old stories, the old Narnia. Almost as if C S Lewis was some kind of apologist defending it from inauthentic visions and alternative myths.
This is such a horrific betrayal. Lewis devoted much of his literary criticism to defending the importance of Stock Responses in literature, to the need for us to see witches as bad and heroes as good; darkness as a danger and light as a glory.
It is not The Magician's Nephew; it is The Last Battle, and as we know, in this world we lose.