It's unfortunate, but it wouldn't be the first such sale, and won't be the last. Governments see how much they can make by selling their land in city centers and moving to office buildings, and they never really consider the intangible benefits of keeping a visible presence in the middle of town.
If I recall, didn't the Dutch previously sell part of their land on Wireless in the late 80s? And the Spanish sold their property just up the road in the early 90s, and of course the UK sold the front of its embassy, and then the rest. Sad.