I know of a large holding company of luxury jewelry goods that has space in the building. For them, its not just cubicles. It would be a very poor publicity stunt to kick everyone out of the building in order to install racks and servers in every room.

Other companies have enough leverage in non-internet related fields to cause a big shitstorm if it was to happen. If this is a long term approach I could see them not renew or assign new leases when current tenants vacate, but you will not see press releases. I also have no association with this story, so I can only speculate as well.