Nintendo’s digital account management (or lack thereof) may have a surprise consequence for used console buyers.
Nintendo locks game purchases to the specific console they’re purchased on. That means even after wiping the console back to factory defaults, the eShop picks up on an element (likely the serial number) and allows those purchased pieces of software to be redownloaded to the same Wii U. When a previous owner sells their Wii U, the serial number doesn’t change. No personal information resides on the unit after being wiped, but the eShop is unaware in the change in ownership. That means free software for the new owner.
Of course, there is no specific way to know what games you’ll get – if any – so it isn’t advisable to snatch up Wii U’s in bulk hoping for a score. However, if you’re looking to sell now in the future, assuming this is a loophole that stays valid, there is a selling point you might want to make to any prospective buyers.