I think it's unfortunate that they feel pushed to have a blanket policy. Not all images hold themselves out to be representative of a specific truth. If an article calls for an illustrative diagram of, e.g. a generic manifold representing energy associated with points in a parameter space, in context, readers should understand it as a hypothetical case whose specific attributes are not the focus, and there isn't really an opportunity to be 'misled' by it. If an article needs a microscopy image of tissue that has been treated by some factor being studied, then swapping in a DALL-E image in place of one produced through actual microscopy (and post-processing) _would_ be misleading. But the context of what the image purports to represent is critical.