Tech enabled homes, for example. Converting malls into homes, and managing building complexes using a tech stack...
If you really can't figure out one single use for cheap empty space, man, you need take a step back and just play around with your imagination a bit :)
I can think of plenty of uses of empty space. Housing is just one of them. What I didn't come up with was any need that tech companies might have. (I hadn't thought of datacenter, which another commenter mentioned, but I doubt the space opening up will be particularly useful for that.) Regardless, I've not heard of any tech companies needing huge amounts more space recently. Starting a new housing company to use this space might make sense, but I doubt any of the tech companies have any desire to become housing companies. I guess I could be wrong. If they do, I'll be removing any investments I might have with them, though.
If you really can't figure out one single use for cheap empty space, man, you need take a step back and just play around with your imagination a bit :)