I agree completely. The target audience Facebook is concerned about is not techies wanting to know the technical issues. Its the huge advertising firms, governments, power users, etc. who have concerns about the platform or have millions of dollars tied up in it. A bland statement is probably the best here - and even if the one engineer gave accurate useful info I don't see how you'd want to encourage an org in which thousands of people feel the need to post about whats going on internally during every crisis.
There will be plenty of time to blame someone, share technical lessons, fire a few departments, attempt to convince the public it won't happen again, and so on.