What if the attacker is already in the system, and using this announcement as a probe for response and as an opportunity to harvest more info?

(ie announce server x is going to get attacked, and stand back while logged into server y and monitor where/who the increased security presence and attention is coming from, and use that to target the next sigint / humint attack)

That seems like a bit overkill for a random publicity stunt.

But a pretty solid plan for someone doing actual corporate espionage.

I hope you work for the good guys.

This sounds like a plan to get them to act now, use that info then to execute the deletion.

While if they don't respond, he won't succeed.

Probably far fetched but seems like a cool mind game

Have you ever seen a line of a source code? Multiply that by million to arrived at Facebook size.

Clearly they wont make a source code evalution in few hours they have. This is not to say “im gonna rob wells fargo at corner of palm street and oak tomorrow at 11am”. This is to say “tomorrow at 11am i am going to rob one of 10,000 wells fargo units”.

Maybe this is a red herring/diversion and the actual attempt will occur at a totally separate time?

True, distracting the public, kind of like the first episode of Black Mirror.

Are you sure it's not more like announcing you plan on robbing the local gas station on X date?

Fort Knox? No try again