pronomono said:
I sent their DPI division an email asking for information or official documentation relating to the Watchtower Bible and Tract Society's previous NGO association and never received a reply in my inbox or junk mail.
The UN had initially been overwhelmed with enquiries regarding the WT's association as an NGO. It is not the UN's purpose to answer questions about who is associated with them and membership is probably a non-issue to anyone other than JWs.
Since so many were interested in the matter, posting the info was likely the easiest and least resource intensive method to provide information to everyone interested.
As the letter is no longer a current matter to the UN, they moved it to the archive site where it remains accessible but not as part of the UN's main website. The archive link notjustyet posted, clearly indicates the link to UN.org.
JWs remain suspicious of any non-favorable information as they blame "apostates" for making it up so I understand your desire to reference the letter directly from the UN. A problem remains: Even when the letter was posted on the UN's main site, JWs would often state that apostates hacked the UN website and posted the letter without the UN's knowledge.
The fact that so many active JW's deny that the WT ever would be associated with the UN is a positive thing. When factual evidence is finally accepted by a few JWs with ability to think and reason, it has prompted some of them to look deeper into the WT's teachings and history.