Fresh in they want it cooked "fresh". People do it all the time because they are under the idea that the food just sits until sold, and it's some life hack to demand it be made fresh. People do it with fries all the time, or they'll demand "no salt" (forcing someone to make it fresh) and then once getting the food, ask for a shit ton of salt packets (the salt will not stick to the fries at this point). For sure, not all McD's hold themselves to the corporate standards, but I'd say a fair number do.

Its especially silly to ask for it to be "made fresh" during rush, since they're likely cycling through everything in minutes.