According to this article, "[t]he Boy Scouts built the historic structure in 1928 and then deeded it to the city, which in exchange agreed to let the scouts use it in perpetuity rent-free."

If the city really did agree to let the Scouts use the building rent-free in perpetuity in exchange for deeding the building to the city, this is a contract. States, or their subdivisions, are not allowed to pass laws that break contracts. See the U.S. Constitution, article 1, section 10, which states "No State shall ... pass any ... Law impairing the Obligation of Contracts...."