The CEO doesn't even know what he is talking about and then had to take back his words. Like some people have a doubt that Binance has lost even more funds that they don't want to disclose and he is very well aware that even other exchanges have been hacked but never such a thing like a rollback has been ever talked about. It's foolish of him to even make such a statement.
It didn't came for his own mouth, it was proposed to him and others chime in and CZ ask for advises as well. But obviously, he don't know what is this proposal and then when he weigh things down, it doesn't make sense to do it. So let the hackers get that 7000
BTC and have those forensics blockchain expert to track it down. And there are also exchanges who are monitoring the address and will block it the moment they see it entered within their environment.