This is a ridiculous allegation.
There is no promoting of the UN in these articles any more than the apostle Paul promoted the Stoic poet Aratus in his speech on the Areopagus at Acts 17:28.
These WT articles merely reference the attempts of the UN to promote beneficial strategies for the human family, and highlight it's failure to accomplish what can only be achieved through the administration of Jehovah's kingdom, the only viable government for this earth.
These assertions, and others like them, are filling up the measure of the activities of Haman (Esther 3:8).