That said, Wikileaks was very proud of its "reporting" track record, methods, and sources. Their minimal exposition was journalistic cover for their original sources that was typically so thin that it would be difficult to contain errors.
Based on that track record and lengths Assange has gone through to maintain that integrity, I tend to believe who he says his source wasn't, that he would not intentionally reveal a source - living or dead, and that their are likely intermediaries or collaborators that would be compromised even if the original source would no longer be affected. That chain of trust is how they help ensure other leakers come to them first, and it seems their opsec is good enough to keep those sources secret even when the organization is significantly compromised.
I completely agree that they often oversold their releases. There were often claims of a deadman switch as well. If that hasn't triggered after all that's happened, was it a bluff? did it fail? was it compromised? did it contain information about the wrong target?
1. Assange really will choose to say who is or isn't a source (that carries its own risks in so many directions...).
2. Assange actually wants to tell the truth about the source...
3. Assange actually KNOWS the nature of the source? If Bob comes to him and says he's from Brazil (random country selected) and he got the info from Australia (another rando country) ... how sure can Assange be?
I'm not sure I find Assange to be a reliable narrator. The nature of wikileaks has for a while felt like it wants to craft its own narrative rather than just release information. Even as far back as when they were on Facebook (not sure if they still are) any question that seemed to even be distantly critical was deleted. They'd announce a big upcoming leak and nothing would happen ... if you asked anything about it your post was deleted.
I felt like they were playing their own game(s).
But even if that isn't the case, I don't trust that Assange can be as sure as he sounds about where information comes from. If he just up and trusts what his source tells him or just assumes he has the resources to be sure, that's kinda naive...