For me, the entire point of Wikileaks is that it is a secure way to leak anonymously designed by a crypto theorist and expert. The security involved with this WSJ thing is opaque, and sounds loosey-goosey based on the Delany paraphrase here. I think they would have been better off trying to get Openleaks off the ground, because Domscheit-Berg seems like he has a model of being a trustworthy technical middle man for traditional outlets.

My bet is that the WSJ is not comfortable with actually not knowing the sources of the leaks - the security sounds like its goal is to prevent intrusion by external entities, rather than to anonymize.