Come on, folks! Dream bigger, here!!!
$7 Billion dollars toward the arts, and your first thought is to build/renovate some Broadway theatres, to serve commercial producers and landlords?
How about none of it goes to commercial theatre, and how about none of it even goes to New York City? NYC is already has one of the most prominent arts infrastructures in the world. Surely we don't need that money most.
Many people in this country don't think it's worth investing in the future of the arts, and Geffen's money would be best spent by helping to change that on a foundational level.
Start with communities that have barely any arts infrastructure at all, either by funding arts education, or by giving local theatres more resources. This could be enough of a reward in and of itself, but it also has the potential to yield larger cultural "returns" on the investment. Best case scenario, it helps cultivate a community-wide appreciation for the arts that will result in more people supporting the arts in other capacities, either with their own money, or by lending popular support to government-funded initiatives.