Good news - experimental verification of the law of supply and demand! I'm sure the analysis is welcome though and I hope policy makers try to learn from this. We could densify most american cities quite a lot more.
Developers not recouping their investment will discourage less housing in Austin in the future and it will become expensive again. A lot of our current housing shortages are from the build up in 2008 and an implosion of the entire industry (so that crafts people did not really exist for the next need for housing).
Last time I did the back-of-the-envelope math, financing permitting delays in San Francisco added 10% to the cost of new housing [1]. (Note: not the cost of permitting. Just the cost of financing the delay.)
This is deadweight loss that everyone in the transaction wins from eliminating. One could absolutely see lower prices and higher developer margins if this waste were cut.