A briefly public commercial has pointed to 5 August as the release date for Pokémon Pokopia's first paid expansion, Bubbly Basin — though the date remains officially unconfirmed.

Eurogamer reported on 29 July that a commercial tied to a Nintendo Direct dated 6 September 2026 briefly appeared on YouTube before being set to private. The ad indicated a 5 August launch for both the Bubbly Basin DLC and a free update enabling underwater building. Eurogamer characterised the date as unconfirmed, given that the commercial was pulled and no formal announcement has replaced it.

The official Pokémon Pokopia website's expansion page does corroborate the broad window, listing Part 1: Bubbly Basin for August 2026 without naming a specific day. The page also describes what players will find when they get there: an underwater town to develop, continuing the "slow life" sandbox gameplay that defines the base game. Koei Tecmo, one of the game's three co-developers alongside The Pokémon Company and Game Freak, calls Pokopia "the first slow-life sandbox game in the Pokémon series" on its entertainment business page.

Bubbly Basin is the first of three paid DLC releases included in the Pokémon Pokopia Expansion Pass, which was announced during Nintendo's Direct presentation on 6 June 2026 and is available for purchase now on the Nintendo eShop. The pass is also name-checked in Koei Tecmo's investor materials for the fiscal year ending March 2026, which were published on 29 July — a signal that the publisher expects the add-on content to factor into its current financial results.

Alongside the paid DLC, a free software update officially named Pokémon Pokopia Version 2.0 adds an underwater exploration ability called "Dive," which players use to reach and explore the Bubbly Basin area. The update and the DLC are indicated to launch on the same day. Several Pokémon are confirmed for the new content, including Mudkip, Crawdaunt, Staryu, Starmie, and Sharpedo — all water-types fitting the expansion's aquatic theme.

Pokémon Pokopia launched on 5 March for Nintendo Switch 2, per Eurogamer's release calendar. For fans, the Bubbly Basin DLC represents the first real extension of that world: new territory to build in, new creatures to encounter, and a fresh reason to dive back in — if the 5 August date holds.