Well, first thing we’ll definitely be getting from the dev team (or at least a sizable number of them) is Splatoon 3. Which will probably get about a year or so’s post-release content itself. But I could see a smaller spinoff in that time potentially being possible, though I wouldn’t guarantee it by any means.
With Animal Crossing spinoffs, it’s kind of hard to think of possible expansions of the core gameplay that aren’t interior design, and I think gameplay expansion tends to work better for Animal Crossing than ‘a totally new thing with a themed repaint’ the way Amiibo Festival was Mario Party but worse. But I could see a few that could be interesting.
Probably the biggest one that could eventually fold back into the main series would be an HHD-style expansion of Pro Designs sort of thing. Maybe you work alongside Label to get the Labelle brand as big as Gracie’s, or you’re a fresh new employee at Graciegrace yourself determined to prove your mettle. Villagers are looking for certain criteria (color, style of item,) and you help design clothes that meet them. (If you’ve played Style Savvy, I’m thinking a bit like the customers there, but with a design element based off AC’s Pro Designs, albeit probably a pretty basic set of metrics to judge against.) The issue, of course, is that once you add an online component to show those designs off you need to add heavy moderation. For obvious reasons. It also seems like doing something like this would be TOO ambitious for a smaller spinoff game, so it’s probably best I hope instead for another Style Savvy that makes custom designs a centerpiece again after they were simplified in Styling Star. (And there’s probably a reason why custom designs in Style Savvy have always been simpler than I’d like in my heart.)
I think a game focusing specifically on critter collection would be really cool, but I’m not sure how much you could expand while still feeling like Animal Crossing. Honestly my most likely idea for that one WOULD be essentially a repaint of an existing game franchise… the long-dead fishing RPG River King. But you’re a seasports streamer like CJ. (Chip is also there, but I can’t resist the urge to go more in-depth with the phrase ‘seasports.’) This might work better than Amiibo Festival mainly because Nintendo’s never really done a fishing RPG like that before except that one Mii Plaza game, so they’d be adding their own spin on it. And anyway, RK’s last release was for the Nintendo DS and by now the field’s diversified just enough with recent Fishing Games that there wouldn’t be the same Amiibo Festival problem of ‘this is clearly a game you already made, but a sad and shallow version of it.’ Less clear template, more room for improvisation. Could be cool. That said, it would have to significantly deepen the fishing mechanics from the games, and I wouldn’t want them changing in the mainline title. Alternately, maybe a title focusing on collection that expands the number of critters and such by removing the town-building mechanics because you travel the world (read: These specific environments, but much more environmentally varied than the typical island) in search of rare insects, fish, and deep-sea creatures for the Fareay Museum or something. Finally, we no longer question what fish native to the Amazon River and goldfish in ponds are doing in the same environment. I don’t think it’s likely they’ll make a full sim-RPG, but it could be cool.
I actually think Amiibo Festival COULD have worked with, you know, actual minigames and less of a focus on Amiibo, but that ship’s sailed and I don’t really want to see an Animal Crossing Board Game release unless it’s some kind of multiplayer aspect in the next full game. The trust is gone. Show me you CAN do the concept well again before I’m willing to buy it as an actual game.
All that said, if we do get an AC spinoff I see it being something we didn’t anticipate at all.