I see no reason why they should stop withdrawal without any form of notice if it is as a result of technical issue, but wait, what are you still doing with exchange like Hitbtc when we have other reliable exchanges. You dont have to invest in any coin you dont find on reliable ones like Binance, bittrex and other top exchanges. HitBTc is one hell of an exchange that registers scam projects a lot and most of the projects on it end up turning shitcoin. You must have got yourself involved too in some of these shitcoin that made you to consider that exchange for use.
Of course, unless there is now really a big problem with HitBTC and they deliberately stopped withdrawals for possible exit scam later (hope they won't do that as I believe that this exchange can still survive). I am aware that HitBTC is deluged with many complaints big and small and that is why I am always careful in dealing with the site and just use it when the token is just using HitBTC and nothing else. There are now many good and reliable exchanges and it is time that we deal with reliable ones with exceptional customer support and more user-friendly platform. Let's see if HitBTC can weather this crisis or will this be its end?