I agree that mostly it is PR, but there is more behind it. Recent hack was carefully prepared fro month. Hackers used fishing technic to gather data and kept till the date of attack. I believe a lot of people so this fishing attempts, but were clever enough not to give any information. How many of them reported them to Binance? If Binance new about these strange activity they've could to do smth (or maybe not). Such statements will lead to people strating reporting all strange activity. No one will receive money for that, but Binance will get the information and will look more reliable. It is a win win situation.