In the 1940s the government of Canada built some office towers out of wood for the duration of WWII, with the intention of taking them down after the hostilities were over. They building were emptied in the mid 1980s and demolished in the mid to late 1990s. Apparently they were still strucurally sound even then...

So by the MotherCorp not converting, will those transmitters still be there fifty years later?