I am pretty sure at this point that these fake UN emails advertising cushy job postings and free travel to UN conferences are just elaborate phishing schemes hidden in UN-ese double-speak. This suspicion was confirmed when "Ernest" commented in a previous post here about his experience in replying to the "Youth conference" email:
Ernest, don’t book that reservation! They will just steal your credit card information and/or identity and use it for all sorts of nefarious purposes.
If anyone else hears back from these phishers, I’d love to know what kind of malarkey they are spewing.