A post on Pokémon's official Japanese account on X (formerly Twitter) notes that while there has not yet been a determination on when the Pokémon Bank service will end, these services may be terminated in the future, and suggests players should transfer their Pokémon from Pokémon Bank to Pokémon HOME ahead of time.
In conjunction with the shutdown of 3DS online services, service for all features of the Nintendo Badge Arcade will also end, and the software will no longer function. While players will continue to be able to decorate their Nintendo 3DS HOME Menu with badges acquired from the Arcade, only the contents of player's badge boxes at the time the service is discontinued will be remain available.
This sunsetting of features explicitly does not include remaining eShop functionality on either the 3DS or Wii U consoles, and at this point in time, Nintendo has stated that users will continue to be able to download update data and redownload any previously purchased digital games for the forseeable future. Given that it's still possible to download Wii titles, more than 4 and a half years after the Wii Shop Channel closed to new sales, it's likely that purchases will remain available for many years to come.
- Sources
Nintendo Support: Announcement of Discontinuation of Online Services for Nintendo 3DS and Wii U software
en-americas-support.nintendo.comNintendo Support: Information on Nintendo Badge Arcade Service Discontinuation
en-americas-support.nintendo.com