Metatrader is just a trading platform and it has no relation to blocking trading account.
I have no idea which resources you read but I know pretty many traders who trade on mt lineup platforms and feel happy with that. You should analyze the information about the broker, its history of operation and official regulation. More than that, before starting working with some brokerage, you should read the rules and regulations very attentively in order not to be blocked. I have come across so many situations when the traders violated the broker's rules without realising that. In addition to that, pay attention to the regins where the broker has the right to work. I mean that if you are in Europe and the broker doesn't work in the EU, don't try to avoid this, don't use VPN and don't provide the broker with the fake information about yourself as this will end up with block of your trading account eventually.