I would doubt this. I've seen folks get their drinks in disposable "to go" cups, but I've never seen a disposable pitcher around Epcot. As a PP said, you're free to walk around the park you're in with the drink, but it cannot be taken outside the gate. They'll make you stand inside the park and finish the drink. You see this happening pretty frequently at Epcot during F&W.
Except Be Our Guest in the Magic Kingdom. They won't let you take an alcoholic drink with you outside the restaurant.