I do see that she has come to realise that 'children's books: not the easy option',from trying to write one, because have we not, my dearios, seen an awful lot of celebs who think any fule can can write a kiddybook?
But, might we not also see in that article that she seems also to be coming round to the notion that fantasy is Not A Bad (or at least, a lesser, genre) Thing?
The two categories do seem to be somewhat assimilated, even conflated.
And I really don't think you get very far just by replacing one binary with another binary:
Instead of thinking there’s “literary fiction” and “everything else”, or even adult fiction and children’s fiction, I now believe that there are books with magic and without.
I don't think it's that simple, even if she's using 'magic' in its broader sense?
I think there are still some unexamined assumptions around canon and literary value going on there.