I noticed that many of the restaurants in the park closed a little while before the official park closing time (6pm on Tuesdays). I assume this is so that there aren't people without party wristbands half way through their meals when they should be leaving. I didn't notice which if any of them re-opened after they made sure only party guests were still around.
If you are wondering if the restaurants offered a special menu of party items (like at some of the AP events this past year), then, no, we didn't notice anything like that. But places did have Halloween themed seasonal items (cupcakes, the demitasse cup desserts, pumpkin items, etc.).