Okay Nintendo is starting to put out little teases so I better get my formal predictions in soon.
1) I called the Switch Online Fire Emblem release so I'm going to take that as a prediction for 1/2 a point, but will say we get more with the release of the next mainline Switch 2 game. Either another retro release or a spinoff.
2) I think we will get at least two ports/updates of Wii/Wii U games. Wooly World and another game. Maybe we get a modified NintendoLand using additional Switches as remote gamepads?
3) We will see a Switch release of a classic Zelda game. Most likely Ocarina/Majora from the 3DS up-ported or some missing retro titles on Switch Online.
4) We will see something to do with Smash Brothers. Either a re-release w/ Switch 2 Editions, or a trailer for the next one. You know they don't want to sleep on that franchise.
5) More Switch Online Rare releases! DKR, DK64, and Star Fox Adventures are my primary votes (would love Conker but I suspect Nintendo won't push for that one). Though I do hope we see some of the more niche GBA games they released late in life.
6) More perks for Switch Online subscribers. I think some of these DLCs like Bonanza Emerald Rush will be offered for free like some past DLCs were.
7) Mario Kart DLC. They have been quietly and consistently patching the game and some changes have been quite significant in terms of what they do (actually changing the layout of tracks among other things). It feels inevitable we will get more karts and racers.

Pokemon both continues its sad decline with Gen 10 while at the same time releasing something far better from a technical standpoint on Switch 2 than past games. I think we're at a pivotal point and the series is about to have a revival of sorts when it comes to the games, but it will take another generation for that to be realized. Most likely tied to the first natively developed Switch 2 title (since I am sure the currently developed one is still Switch 1 Native)
9) We will see more from Animal crossing aside from this 3.0 update. Maybe some additional future content for the current game or another spinoff of sorts.
10) Metroid 40th Anniversary will be given a token acknowledgment through some retro releases, but nothing big like it deserves.
I actually struggled to find 10 good predictions. Maybe its where I am at in life but I just can't think of a lot of things that would make sense and believably be done by Nintendo in 2026. I'd love for certain old franchises to be revived, but that doesn't seem to happen too often these days. (and no, dropping old games on their live service isn't a revival). I ended up looking up what anniversaries were happening to get ideas since that seems to be somewhat reliable as a predictor.
It's also the Gamecube 25th anniversary so maybe we get a lot more GC love this year?