Why then was the following statement included in the article?
The land on which the building sits had been turned over to the city by the Scouts with the understanding that the Scouts would be able to stay in the Beaux Arts style building "in perpetuity."
Because it's a sloppily researched article. The land belonged to the city. They leased it to the BSA for $1 a year. The Scouts built the building on it and later turned that over to the city. The land itself, though, always belonged to the city, and is part of the same large parcel that includes parks and public museums. As far as the "in perpetuity" thing, the original agreement includes a clause that allows the city to terminate the agreement with one year's notice.
Because it's LifeSite News...not exactly the most accurate source.