If you did know the plane was taken by terrorists, you would be putting out disinformation to make them believe you were confused and looking in all the wrong places. Also if the passengers were hostages and you knew their general location, you would want time to gather more information in order to put together a rescue mission.
You have made valid points.
I hope for the 230+ plus souls on this plane that this could even be a possible outcome.
There has been diversion aplenty in this saga, no doubt about that.
I like that possibility.