US embassies seem to use a pair of Met One BAM-1020 sensors,[1] which run about $40,000 apiece.[2]
But that's beside the point. The sensors have already been purchased, the sensors are still being maintained, and the sensors are even still recording data. All they did is stop publishing the data.
My $150 air purifier does all of that and working perfectly for 4 years. It gets data and syncs with cloud. I can't think of any reason apart from protest from the Department and cutting high visibility thing that cost nothing.
What is the actual recurring cost of broadcasting this data? The sensor and network infrastructure are presumably already established.