"TBA"
Nintendo at least made reference to Metroid Prime 4 in their most recent financial briefing, but other than that, we haven't heard anything about the game's release date or anything at all.
They really mentioned a good number of games. As of August 3, 2022, this is their first-party big games schedule going forward:
- Kirby’s Dream Buffet — Summer 2022
- Splatoon 3 — 9/9/2022
- Bayonetta 3 — 10/28/22
- Pokemon Scarlet/Violet — 11/18/22
- Breath of the Wild 2 — Spring 2023
- Metroid Prime 4 — TBA
- Advance Wars 1+2: Re-Boot Camp — TBA
Among all of them, Nintendo also made the decision to draw special attention to the following titles for investors: Kirby's Dream Buffet, Splatoon 3, Xenoblade Chronicles 3, Mario Kart 8 Deluxe – Booster Course Pass: Wave 2. By the end of September, all of those goods are categorized as "near future." Strangely enough, nevertheless Dream Buffet still just has a "summer" date; the brief lists it in the "by the end of September" category, implying a release window (summer most likely confirmed that anyway, but it doesn't appear like this will be delayed just yet). In appreciation of Splatoon 3, the business also informed everyone that a new Switch OLED model was coming on August 26. Unfortunately, both Advance Wars and Metroid Prime 4 are still TBA.
Since Nintendo noted in that same brief that "sales were also steady for add-on content, including Animal Crossing: New Horizons - Happy Home Paradise" and many of the aforementioned games have some sort of DLC or season pass content already announced, or probably in the works, it appears that DLC is the strategy for long-term growth.