Nintendo revealed earlier this year that it plans to shut down the eShops for both the Wii U and the 3DS. Unlike PlayStation, Nintendo is yet to make a u-turn on that decision and has now revealed the exact date on which both eShops will lose the majority of their functions. March 27, 2023.
The news that the two consoles launched prior to the Switch would be losing their eShop support was officially confirmed back in February. That was followed by the ability to add funds to your accounts through the eShops ending in May. Nintendo has now confirmed the next steps in the store closures, including the reveal that support for the stores will end for good on March 27 next year (via Nintendo Life).
That means from that day onwards, you will no longer be able to purchase games through the Wii U and 3DS eShops. If your reaction to that is a shrug and you'll just find physical copies of the games you want, the resale prices for boxed games on both consoles will undoubtedly go through the roof once the stores close next year. You will also be unable to download demos, free-to-start games, or redeem any codes.
Don't panic, your consoles won't become obsolete from March 28, 2023 onwards. Even though support for the eShops will come to an end, you will still be able to redownload games and DLC you have purchased in the past. All of the 3DS and Wii U's online capabilities outside of purchasing games will remain intact too. Nintendo also announced you will no longer be able to add funds to your account via an eShop card from August 29, 2022, but will still be able to redeem download codes right up until March 27.
PlayStation attempted to pull a similar move to this one last year when it announced it would be closing its PS3 and PS Vita storefronts. Backlash was fierce enough that the decision was quickly reversed and the stores will remain open for now. Ubisoft also made the controversial decision to end support for a number of its games recently, meaning DLC and online features for many of them will become inaccessible.