I think Twitter would face a giant lawsuit if they did that.   The intercept said it was leaked by a member of the group.  They used his credentials to log in and verify the messages. The group referred to it as a low security communication and they obviously communicated by other means.   Assange reached out to someone he thought was Sean Hannity recently and said he had material on a US Senator who is part of the Senate Russia investigation and he mentioned needing to talk through other means.    Assange seems to share your anti-semitism.