As far as we’re aware, Wii Us have NAND chips from three different manufacturers: Hynix, Samsung, and Toshiba.
— OatmealDome (@OatmealDome) March 18, 2023
You basically have to win the lottery and happen to buy a Wii U with a chip from a “good” (non-Hynix) manufacturer to 100% avoid this issue.
(thanks Maschell)