They redid the textures, the lighting, the effects work, practically every aspect of the graphics, that's definitely a full facelift in my book.
You are mistaken. The textures used are the original high-resolution ones created during development of the original game, which used scaled-down versions of the textures to match the GameCube's hardware capabilities.
Practically all the aspects of the graphics are the same as the GameCube version, handled in higher fidelity on the Wii U due to its more capable hardware. That’s not a full facelift at all.