Apparently the rolls royce engines have a remote debugging ability that was not enabled on this flight, however it was still pinging home which is how they first noticed the course change. They had disabled all the other trackers, so if they were watching the news the chances are they have disabled these too.
If the plane is parked in working condition somewhere on this planet, thanks to the media coverage the hijackers now know that the jet engines will phone home the moment they start them.
But then again, this is hypothetical nonsense. The plane most probably crashed into the ocean.
If the flight starts another journey from wherever it is, will it be possible to track it via radar ?