Gate.io have active complaints on reddit, and I did not find a complaint that talked about problems with withdrawal. https://www.reddit.com/r/GateioExchange/ However, Gate.io may restrict or block access to its services in some countries, so always be sure to check your country in the special list https://www.gate.io/user-agreement
So perhaps people are really buying BCN on gate.io and are able to withdraw from gate.io to their BCN wallets?