My understanding is that the post isn't the x-risk- a UFAI could think this up itself. The reaction to the post is supposedly an x-risk- if we let on we can be manipulated that way, then a UFAI can do extra harm.

(Concerns not necessarily limited to either existential or UFAI, but we cannot discuss that here.)

But if you want to show that you won't be manipulated a certain way, it seems that the right way to do that is to tear that approach apart and demonstrate its silliness, not seek to erase it from the internet. I can't come up with a metric by which EY's approach is reasonable.

Agree. :)