Why??? Would they not play 300 miles from the coast.
Because people travelling to and from the game are not all from places 300 miles from the coast.
Also, by the time the game is over, Ike is not going to be on the coast anymore, it is going to be hours from Austin. It may not contain hurricane force winds, but 65 mph winds can do some damage, as can driving rains.
Putting on a football game requires a lot of support. Police, EMS, first aid, volunteers, etc. Not only the people who are in those rolls working at the game, but those that perform those duties who might be there as fans.
Last, if there is going to be heavy evacuations, there are not many hotels between the coast and the 300 miles to Austin. Austin could be a main evacuation point and the rooms booked with fans from Arkansas and Texas could have those booked for obviously non emergency events.
Ike is a big f*(king storm.