The NSA’s Spy Hub in New York, Hidden in Plain Sight

>... 33 Thomas Street is the only location in New York City where AT&T has an FCC license for satellite earth stations.

That licence is for transmitting (uplinking). You wouldn't normally want to have a satellite surveillance installation in a place with active transmitters, even if those transmitters are on bands different than what you are interested in. You wouldn't want such an installation in a major city where there could be interference. Since it could be placed pretty much anywhere you would normally just pick some place out in the country. The result of that monitoring could then be sent somewhere less remote.

Perhaps the reference is to the monitoring of AT&T satellite traffic that happens to pass through that particular communications nexus.

The blank building is common globally for its period as they allowed good temperature control and a lot of telecommunications equipment with 12 foot high racks and overhead busbars and cabling. However they're terrible places to inhabit all day long and one building I know has a window put in, bearing testament to the strong willed manager and their concern for staff. It really helped make it tolerable.