Spartz isn’t a “public official”, so maybe the standard is laxer here?
The relevant category (from newer case law than New Your Times Co v. Sullivan) is public figure, not public official, which is further distinguished into general-purpose and limited-purpose public figures. I haven’t looked for case law on it, but I suspect that being the cofounder of a 501(c)(3) is probably sufficient by itself to make someone a limited-purpose public figure with respect to discussion of professional conduct within that 501(c)(3).
Also, the cases specifically call out asymmetric access to media as a reason for their distinctions, and it seems to me that in this case, no such asymmetry exists. The people discussed in the post are equally able to post on LessWrong and the EA Forum (both as replies and as a top-level post), and, to my knowledge, neither Ben nor anyone else has restricted or threatened to restrict that.
The relevant category (from newer case law than New Your Times Co v. Sullivan) is public figure, not public official, which is further distinguished into general-purpose and limited-purpose public figures. I haven’t looked for case law on it, but I suspect that being the cofounder of a 501(c)(3) is probably sufficient by itself to make someone a limited-purpose public figure with respect to discussion of professional conduct within that 501(c)(3).
Also, the cases specifically call out asymmetric access to media as a reason for their distinctions, and it seems to me that in this case, no such asymmetry exists. The people discussed in the post are equally able to post on LessWrong and the EA Forum (both as replies and as a top-level post), and, to my knowledge, neither Ben nor anyone else has restricted or threatened to restrict that.