The mammalian visual system has been the predominant model system used in developmental neurobiology research for the past fiftyish years. It's generally known at this point that visual circuits pattern themselves according to input, and that visual systems fed from a constrained input domain lose the ability to meaningfully represent real-world input. We also know that computer displays show a very restricted subset of perceptual info, and also don't relate to other sensory modalities (like proprioception of head/eye movements to look at peripheral objects) which are important for maintaining an integrated environmental map. So, it's more reasonable to assume that looking at monitors is harmful than helpful, especially at a young age (or following a stroke, taking certain HDAC6 inhibitors or other things that increase "neural plasticity"). The common knowledge of developmental neurobiology has advanced to the point where the claim "closer to natural ISN'T better for normal development" is one which requires proof.

Now, does this have any meaningful bearing on e-ink displays? The contrast ratio is closer to stuff you get in the natural world, but apart from that it's still a monitor.