This is only going to happen in the longer term if at all because the construction standards and rents for commercial buildings are so much higher. Most likely

This is only going to happen in the longer term if at all because the construction standards and rents for commercial buildings are so much higher. Most likely is that alternative commercial concerns find uses for these spaces at least in the short to medium term. It is also the case that a lot of manufacturing, light industry, fashion, and other such got pushed out by tech over time and could potentially move back in.