How do we know EY isn't doing the same?
Indeed. Given a lack of transcripts being released, I give a reasonable amount of probability that there is a trick of some sort involved (there have been some proposals of what that might be, e.g. "this will get AI research to get more donations"), although I don't think that would necessarily defeat the purpose of the trick: after all, the AI got out of the box either way!
Todays xkcd
I guess there'll be a fair bit of traffic coming from people looking it up?