Board Thread:News and Announcements/@comment-24264457-20180925194341/@comment-1465604-20180926065058

@ThePokémonGamer: Monthly Mash-Ups are 100% on-disc content. What happens when you unlock them is that a tiny bit of code is embedded into your save file to tell you that they've been unlocked. So, technically, information that keeps them unlock is stored in the savefiles.