Foreclosed, as if they are paying a mortgage or something? A buildings value is based on it being prime property or being a swamp. Only using it for festivals, as far as taxes are concerned, is totally irrelevant. besides, they are in the Reedy Creek municipality so they would only be taxing themselves anyway. No taxing body would even consider to have a lesser value just because it was empty at this point. That is more of just a mistake by Disney for having property and not attempting to use it to generate revenue.
Body Wars mechanical's are gone, missing, AWOL, departed, released from bondage and so on. They are just empty rooms at this point. Nothing to wonder about. Unless they come up with something new to need a simulator, it will just be a storage basement.