OLED seems like a no brainer for a lifecycle refresh at the ~3-3.5 year mark. Particularly because they've done it before, and Valve very recently proved it's still a viable way to boost sales. Nintendo has had 7 years to prepare for this launch they likely have every mario, zelda, metroid release date pinned to a particular month and year through at least year 5. A display upgrade mid cycle is almost a given.