IATA has no reason to care if their list were to say appear on wikileaks as a one-off incident. Subscribers to the list would still continue paying the extortionate rate for info because it's always being updated.

Someone could derive the list by having a script that harvests connecting flights from a consolidation site that will only show you single booking flights (like ITA). In fact, ITA would be a good site to harvest, because ITA s/w doesn't care if someone scrapes from their site.