They can already do this now. It might not be down to the minute but if someone plunders you on Tuesday, waits around for your buildings to pop and there was nothing there at 5:10 but at 5:15 there was, nothing is stopping them from sharing that info now.
What steps do you take in the game as it is today when you get plundered?
Will that change if more then one person plundered you today?
Do any of those work against a player with a GB with Espionage?
Against a dozen players in your hood with Espionage?
Are they really going to sit with your city loaded waiting for it to pop
Why would I wait around? I plundered you yesterday at 11:30. Today I'm going to use Espionage some time before 11:30. I'll be back 2 or 3 minutes before you are going to collect and break your defense again, Then it's a game of Roshanbo. Will you collect the building before me? Can you win Roshambo against a dozen plunderers at once?
Do you run multiple cities? Think you can manage them all in whatever way you are trying to dodge being plundered?
That's OK, we;ll be back every day. When the hood switches, they'll do the same. How much time are you willing to wait doing uour collecting? Are you willing to do that every day?
Or maybe it's better to not have this ability in the game?