"Any advance notice on these actions would have allowed bad actors to alter their behavior to evade detection."
Alternately: Everything we do must be top secret, and it's definitely not because we're totally making it up as we go with zero actual planning or testing. We pinky swear.
I guess it's almost an improvement on their poop emoji default non-reply. It looks like this problem was big enough for them to do active damage control; Musk must have been real pissed off.