Netflix has confirmed via the official Nintendo support page that they have discontinued updating the Nintendo 3DS and Wii U apps. The Netflix app was removed the eShop on December 2021, however if you had the app installed updates were provided, but as of now it has been discontinued. I’m not sure how many people were using Netflix on their Wii U console or Nintendo 3DS, but I would imagine it was a fairly low number, however, I could be completely wrong. Sadly there’s still no news of a Netflix app for the Switch.
The Netflix app was removed from Nintendo eShop on Wii U and Nintendo 3DS Family systems on Dec 31st, 2020 and discontinued on June 30th, 2021. Thank you for your support of these applications over the years.Nintendo support page