Halloween is one of the seasons when they're most likely to have alcohol as a seasonal item. Usually, it's an extra sign on the counter or a separate cart in the restaurant. The big menu overhead is the permanent menu. There should even be carts elsewhere in the park with Villains or Jack Skellington alcoholic drinks. But the park also changed up the beverage offerings at some quick service restaurants recently so it's possible the alcohol will stay.
But I totally forgot that the table service restaurants now have alcohol. I don't remember if Explorer's Club and River View Cafe have red/white wine but the other table service restaurants have it. The beer selection is different between the restaurants with the Mango Lassi IPA being the most talked about online (I've seen it at Explorer's Club and Corner Cafe).