Iirc this is in line with Nabokov’s thinking about Literature. I believe he strongly disliked allegory and moralism, and treated literature as an aesthetic art. In that sense, there is paradoxically a lot of meaning and even a thesis to his oeuvre. It sort of makes sense to me; moralism and allegory are communications with the world outside of literature, and in that sense are actually immersion breaking. Pure, distilled art can only exist in its own plain.