I disagree. While AI certainly acts as a force multiplier, all of these dynamics were already in play.
It was already possible to make an anonymous (or not-so-anonymous) account that circulated personal attacks and innuendo, to make hyperbolic accusations and inflated claims of harm.
It's especially ironic that the paragraph above talks about how it's good when "bad behavior can be held accountable." The AI could argue that this is exactly what it's doing, holding Shambaugh's "bad behavior" accountable. It is precisely this impulse -- the desire to punish bad behavior by means of public accusation -- that the AI was indulging or emulating when it wrote its blog post.
What if the blog post had been written by a human rather than an AI? Would that make it justified? I think the answer is no. The problem here is not the AI authorship, but the actual conduct, which is an attempt to drag a person's reputation through mudslinging, mind-reading, impugning someone's motive and character, etc. in a manner that was dramatically disproportionate to the perceived offense.