Please, tell me, what does this all have to do with the Exchange? If anyone is answerable for the 51% attack, this is the developer, but definitely not the Exchange.
Everybody who followed the developments of the situation and wanted to withdraw their coins, did it without any problems. And this is not about luck, but about some people are working hard, following the news, etc., but some, on the contrary, let everything loose, leave things to chance and then blubber in forums blaming everything and everyone.
I have an experience, faced the same situation a few times before, had to withdraw the monies in the midst of delisting - and you know what? - never any slightest difficulty.