Agreed, as I saw that article too, but one interesting thing I also noted was that the U.N. spokesman who declared the document a fake gave this as one of the "proofs" that it was fake:
"The document number (A/CN.11/L.72) doesn't conform to our standard system, in any case."
(This doc number can be found at the top left of the doc, though the QR code at the bottom right references A/CN.10/l70).
So, if that doc doesn't conform to their standard system, then why does this extremely similar doc number (same format, different document number digits) workd just fine:
http://undocs.org/a/cn.10/l.70
<redirects to>
http://www.un.org/ga/search/view_doc.asp?symbol=a/cn.10/l.70
i.e. A/CN.10/L70 is a valid doc number, but A/CN.11/L72 isn't.? Odd.
Honestly, I can't give an answer to that. What I will say is what I stated above - I do believe that the U.N. would be in 100% in favor of what the letter suggests, and I believe our POTUS and others in our government would agree.
That said, I think it is just about impossible that they would say as much in any memo that could be potentially leaked. These people are masters of covert, back-door deals. They simply don't put stuff like this in print. They don't want you to know they're coming for your guns - even though we all know they are.