Nintendo is not happy with the current progress of Metroid Prime 4 for the Nintendo Switch and despite the game being years into development, the company has decided to essentially scrap the existing progress and turn development over from an unnamed third-party studio back to the original creators of the Prime series, Retro Studios. It's such shocking news that Nintendo published a video of Shinya Takahashi, Senior Managing Executive Officer, explaining it all.
Don't expect to see Metroid Prime 4 for another few years now. I wouldn't even be surprised if it became the next The Legend of Zelda: Breath of the Wild and launched on both the Switch and the Switch's eventual successor. Progress on the game must have been abysmal for Nintendo to can it after years of work. Of course, now I can't help but wonder how bad it was, who was working on it, and how hard Nintendo's team tried to help save it before giving up on it. Maybe if we're very lucky, we'll learn the rest of the story someday.