This is actually huge. I'm shocked this isn't a bigger deal here. This will provide a far greater incentive for investments in theatre since it severely limits the downside risk of investors who won't owe taxes on the income until the show makes its money back. It means investors will get their money back more quickly and will be more apt to invest in theatre.
The biggest benefit I see would really accrue to regional theatres and off-Broadway. Since Broadway's theatres are rarely dormant for long periods of time for want of a new show, I doubt this will mean a massive influx to Broadway. Instead it's likely to mean riskier projects off-Broadway and throughout the country that were having trouble securing financing to mount will have the scales tipped in their favor. A good day for theatre!
Scratch and claw for every day you're worth!
Make them drag you screaming from life, keep dreaming
You'll live forever here on earth.