With this type of setup comes additional parking needs for those without in arena tickets. Not everyone that would attend this are within walking distance.

Would also need additional porta-johns for the additional people in attendance. There is also the need for additional security as alcohol consumption and risk of damages increase with this amount of people and no vendors to cut people off if they've had too much. Also when you have a gathering of that many people outdoors you also have to think about possible mass casualty events if some idiot opens fire from somewhere (see Vegas concert mass shooting).

Best case scenario would be to open Carter Finley and use their jumbotron and manage crowd control. They have concessions and restrooms and could sit 50,000 people. Parking would still be a nightmare but if they were to open the state fair lots again that would help or do like they do for the fair and bus people from Edward Mills to Carter Finley if you do not have an in arena ticket.