Even though the Wii used big discs, it still allowed you to insert a smaller gamecube disc and play it. Does the WiiU also let you play gamecube games?
The Wii U completely emulates the Wii. You literally load up the full Wii operating system inside the Wii U. This makes it possible to use GameCube discs with the Wii U. The disc drive will support the disc size just fine.