I own four businesses. The rest of the space is occupied by gaming corporations. It’s been 200+ game days and nothing’s changed, the rooms are not vacated. No movement.
With alpha 9 (coming soon) this should be much better, there should be lots of available buildings.
You can always check the movements in the “Market Insider” app (which also should have more activity with the next version).
Closing this, availability should be okay now.