What do you mean by "empirical"?
Given a putative explanation, how do you assess it?
It appears to me that you are merely saying that you do not accept the putative explanation that the Duck (among many others) accepts. Putting it in the impersonal language seems extremely misleading to me. Moreover, the existence of the disagreement appears strong evidence against the claim this is an empirical question, at least if "empirical" is interpreted in an impersonal way.
Maybe your point is your second sentence and your disagreement is a minor detail, but I find your phrasing emphasizes disagreement and distracts from the second sentence. Indeed, the second sentence seems to take a personal view of acceptance of arguments.
The claim that "materialism will be capable of explaining qualia" is proven if materialism does indeed come up with a convincing explanation of qualia. And while one can't disprove it entirely, the claim becomes quite improbable if we ever reach a point in time where it looks like we've solved every other scientific mystery aside for the problem of qualia.
I have no idea of how I'd assess a proposed materialistic explanation of qualia, given that such an explanation seems to me impossible in principle. But then, just because I'm incapable of imagining such an explanation doesn't mean that it would actually be impossible to come up with one, so I remain open to the possibility of someone coming up with it regardless.
[Cross-posted.]
1. Defining the problem: The inverted spectrum
A. Attempted solutions to the inverted spectrum.
B. The “substitution bias” of solving the “easy problem of consciousness” instead of the “hard problem.”
2. The false intuition of direct awareness
A. Our sense that the existence of raw experience is self-evident doesn’t show that it is true.
B. Experience can’t reveal the error in the intuition that raw experience exists.
C. We can’t capture the ineffable core of raw experience with language because there’s really nothing there.
D. We believe raw experience exists without detecting it.
3. The conceptual economy of qualia nihilism pays off in philosophical progress
4. Relying on the brute force of an intuition is rationally specious.
Against these considerations, the only argument for retaining raw experience in our ontology is the sheer strength of everyone’s belief in its existence. How much weight should we attach to a strong belief whose validity we can't check? None. Beliefs ordinarily earn a presumption of truth from the absence of empirical challenge, but when empirical challenge is impossible in principle, the belief deserves no confidence.