Yeah, I would also put a grain of salt on that news if he's the one who just said that. It could just simply be another publicity for him and Huobi with such actions.
The news of the returned stolen fund has circulated everywhere but I've also thought about what you said. Concerning how they pride the exchange to be unhackable, Justin Sun could easily tweet this to calm all fraying nerves down and to make HTX exchange look good in the eyes of the media. To back up his claim, I would have expected him to attach a transaction id of the returned stolen funds by the hacker.
Justin is a known PR guy with Tron and this could be a publicity stunt and never happened. But for me, what's important and more concerning are the funds of their customers. Since they've got a lot of reach through their social medias, you're right that they can just make story, post and tweet there and everything's fine again.
Aside that, I just find it hard taking his words for it.
Well, we do understand each other with that because of his past based from what he has done and how he marketed his project.
