Well, I would think one should conclude that the inability of human language to directly evoke some previously never sensed sensory experience is a linguistic issue, and isn't a problem to be solved with language, it's just a fact about how human language works.

Getting back to the blog post this was about, it says,

>I argue that if consciousness is only knowable through the unique metaphysical relation we bear to it, then it necessarily follows that other significant phenomena may exist in our universe we don’t know about without the necessary metaphysical relation(s).

Having consciousness is a necessary condition for all knowledge, but it is not a sufficient condition for knowing about a particular thing, even for knowing about consciousness. Before any understanding of how brains work people had consciousness but didn't know what it actually was, that the experience of tasting pistachios was the brain activity resulting from eating pistachios. Having an experience is not the same as knowing what it is. People experience plenty of things without knowing what the experience is.

With language, we can describe what some experiences are like in terms of experiences that a speaker would understand, like people describe various tastes as nutty, or chocolatey, and so on. That way people can sometimes imagine what experiences are like without ever having had them, by their similarity to whatever they have experienced. Hence having had some experience of X isn't always a necessary condition for knowing what X is like, because it could be understood by relation to Y or Z. Or it could be imagined in relation to objective facts. Some things could not be conveyed like that, like the experience of a bat at least largely could not without some kind of mutation scenario or highly advanced implantation or surgical goings on.

>And that's the way you know what it even is. To experience it.

No, perception is one way you can know things, but it is prone to biases, faulty information, illusion, hallucination, etc.. That's why having objective means of measurement or studying things generally is necessary in science, and how e.g. neurology can describe how vision works. Just having vision might lead to false explanations of how vision works. Obviously before microscopes, X-ray imaging, etc., much less was known in biology. [Actually in this instance you probably mean "know what an experience is like", but my point is any knowledge based on that wouldn't be something you could learn verbally, so it's just an aspect of communication. It wouldn't mean someone couldn't know "coffee tastes chocolatey" if they don't know what chocolate tastes like. Facts like that could be known without first person apprehension just based on how the sense work, etc.. ]

Experience gives first person apprehension of some sensory system, but my point was that the inability to convey in language what some experiences are like to speakers who can't have the experience is not a problem of knowledge, at least not something solvable by philosophers like how certain problems are solved in physics to determine experimental results. It's just a brute fact that certain organisms like humans are limited in their senses, and can't perceive beyond them, at least not without some future biotechnology, like to allow humans to sense infrared like snakes or hear higher frequencies like dogs or so on.

>I think it would.

If you were the observer you would, but if you had a nervous system incapable of pain you wouldn't understand what pain felt like. That doesn't mean there is anything verbal to know about pain though, it just means that knowing what pain feels like requires having a nervous system capable of experiencing it.

>Neural activity doesn't inform the observer that it feels like anything at all.

Why would it? Language only conveys what speakers can understand. If a neurosurgeon was colorblind, they could still understand how color vision works without knowing how colors look in the first person, but that doesn't mean there should be a way to convey what those experiences are like even to certain speakers who can't experience them. Having a certain kind of nervous system is a necessary condition for apprehending certain experiences.