It's also not an argument, let alone an argument from authority. It's a claim. Also, your edit of my statement changes the actual meaning of the statement, it doesn't clarify it in any way. I said what I meant and was more correct in that instance. Argument from authority has to do with the authority, not the statement by the authority. Your edit demonstrates a fundamental failure to grasp what "argument from authority" really means.
Argument from authority does not require the authority be false, it requires that the authority be, itself, used as "evidence" of a claim. Looking for "Magisterial" i.e. "authoritative" rebuttal to cite in the future seems like looking for some "authority" on what rationality means to throw at someone, not unlike the "Hitchen's Razor" you're citing as a "bitch slap" which is.... odd.
My response is a direct refutation of THE CLAIM, in that Yudkowsky explains the rational for the prohibition.
Are we to understand you're asking for an authority to cite...for the PURPOSE of "argument from authority" to get your opponents to shut up when you disagree? Some sort of "Rationalist Trump Card?" That...seems strange. But I must be misunderstanding.
The "Berkeley, CA based Rationalist Community Forum" sent you to this a few times. In which EY stated that the infohazard itself, not "emotional brittleness" was the cause. This included a direct statement from EY, whereas the links and sources that suggested "emotional brittleness" were sourced as "rumors."Be careful of DDCT!