"Also land taxes/council taxes etc, I presume?"
It's going back a long time; I may be under the wrong impression: I think one of the scandals about WT back in the day was that as a religion, they didn't have to pay property taxes on their Brooklyn Heights properties. Not sure if they were exempt from NYC rates/taxes/levies, whatever. Critics saw what everyone here knows: the WT was a tax exempt publishing company.
Having the WT move out of NYC was probably a huge boon to the city and the state. And I doubt that there was any of the sadness that sometimes happens when an old institution moves out of a place. It's not like the WT was a paragon of patriotism, either national or local.