A "35-mile radius of the United Nations headquarters" includes literally all of New York City and then some, making the supposed connection to the UN meeting extremely tenuous.

This looks exactly like a "SIM farm" operation, which rents out access to real mobile numbers, usually for the purpose of spamming or fraud. Yet there's no mention of this possibility.

Thank you, exactly this^

There are stories of these SIM farms all the time, here is an example with very similar gear: https://www.vice.com/en/article/video-ukraine-busts-alleged-...

These stories are always sensationalized when their primary purpose by enlarge is probably just spam.