I don't know if it will be open, but then again, I'm not sure why it wouldn't be open, it being a high volume time.
I can say when we were there for spring break, my son really wanted to try it. Service at the window was a little slow when picking up our food, but YUM! We both got the burritos. Although, I would say, think more like an oversized soft taco. The fixings bar was great. One of the best parts was sitting in the outdoor seating area and listening to the theme music from the "Pirates" movies. All in all, a great experience and as a bonus, for a very reasonable "Disney" price, it filled up my pre-teen boy, who sometimes seems like a bottomless pit when it comes to food intake.