That's not very specific, though we can probably rule out the next couple of weeks.
Although it won't have a Mouthful Mode, Kirby's next Switch adventure will still involve mass amounts of eating.
Kirby's Dream Buffet is a 4 player (local and online) competitive game in which players race around food-themed environments collecting food in order to make their Kirby as big as possible. It will be possible to use larger Kirby to knock other players off the course.
The game is slated for a "summer" release, and at least for North America will be available at retail according to a Nintendo press release.
UPDATE 1:21pm ET: Nintendo has clarified that the "available at retail" refers to prepaid code cards for the game (similar to other Nintendo games with purchasable codes), and the game will be considered eShop exclusive.