Go Duke! Now, that I have your attention... In the mid 80s Duke basketball was regaining its popularity. Their arch-rival had just built a shiny new 21,000 seat arena. Duke considered building a new arena as well. They certainly had the resources. They chose to put money into their 45 year old facility. They moved the students to court side, improved amenities and manged to squeeze in a few more seats. As a result they made more money. I don't think ticket prices offset the 12,000 extra seats but as demand went up so did the donations required to get tickets.
My point is... you may lose 5,000 seats if XL goes away, but you can create a better atmosphere and possibly make up the money by making some improvements to Gampel. Plus you are not subject to shifting political winds.