Update []:
The makers of Nintendo Network replacement Pretendo have posted on social media, responding to Nintendo's warning against using unofficial services.
While acknowledging the platform holder's sensible stance on security, the people behind the fan-made service highlighted a commitment to user safety, noting that they have even released "security patches for games Nintendo themselves no longer supports".
Original Story: Although you would think Nintendo's focus would be completely on the Switch "successor" right now, it seems the company's customer support line has found time to issue a notice about unauthorised services for older hardware.
In a brief message on social media, the Japanese branch has apparently confirmed the existence of services that replace functions like "online play" for the Wii U. It's now advising anyone using these services to refrain from doing so, as they may pose a security risk. Here's the rough translation in full:
Nintendo: "[Request] We have confirmed the existence of unauthorized services that replace functions such as online play for the Wii U, which ended service on April 9, 2024. Please refrain from using such services as they may pose unexpected security risks."
As mentioned, the online services for the Wii U (and 3DS) officially ended in April last year. At the time, fan-made network services like 'Pretendo' stepped in to keep online up and running for the community. Pretendo had even got to the point where Wii U users were able to access these services without having to hack their system.
In other words, if you end up having any problems with your Wii U after using an unauthorised service, don't expect Nintendo to help you out. You can learn more about all of this as well as the Wii U and 3DS online shutdown in our previous coverage here on Nintendo Life.