The Wii U cannot play DVD-Video or Blu-ray discs. Its optical drive reads only proprietary 25 GB Wii U discs and standard 12 cm Wii discs. Nintendo skipped the CSS licensing and hardware decoding required for commercial movie playback—a cost-saving measure that also kept the console's price down.
While the disc drive won't help, the console still offers streaming options (while the eShop and servers remain functional):
For reliable, high-quality movie playback, a dedicated streaming stick (Roku, Fire TV, Chromecast) or a modern game console (PS4/PS5, Xbox One/Series X|S) is far superior. They support 4K, HDR, Dolby Atmos, and receive regular app updates—things the Wii U never will.