It will be stolen again if they stay careless about it and that’s the simple case. However, getting the stolen bitcoin back is not going to be very easy. As long as you have the private keys you can play with the whole thing but when you don’t have it then you can just well wander around that’s all.

So your article says that it was a sophisticated hack of the exchange. Sometime I feel that these exchangers are doing all this in purpose so that they can claim the insurance. Is that a thing that’s possible really?

The answer is no, except the transaction still unconfirmed and you have private key or access to your wallet address, then still have a chance to do double spend and send it to your another address with higher fee or contact some miner to help the transaction confirmed faster. If the hacker already stole it and already spend it then its almost impossible to recover stolen bitcoin, even some hacker maybe using some bitcoin mixer and spend it anywhere to make it really hard to track.