What I understand is that they are doing this so that people can not request any withdrawal but this is very unethical business conduct. At this point I am in doubt if this is a scam attempt or buying time.
Then they should disable the deposits of that particular altcoin instead like what other exchanges do, they even announced such update. I really think that this is one of their way to take their users funds and telling that its your fault to send amount when blabla.