Nintendo announced yesterday that the 3DS and Wii U would lose “online play and other functionality” in “early April” next year.
Pokémon Bank for 3DS won’t be affected in the near future, but other parts of the 3DS online service will. As stated in the announcement, this service will continue after other online services end.
To raise awareness, the official ‘Play Pokémon’ social media account has posted about this and advised trainers to transfer their Pokémon to the Pokémon HOME app on Switch and mobile devices immediately.
“Nintendo 3DS online services will be discontinued in April 2024. While Pokémon Bank can be used beyond that date, we encourage players to transfer their Pokémon to Pokémon HOME at their earliest convenience.”
Pokémon Bank will remain available after the 3DS “online play” closure, but Nintendo says it may end “some point in the future”. Later than “online play” ends, the Poké Transporter can be used.