February makes sense for a number of reasons - upcoming titles like Dragon Quest Builders, Bayonetta 1/2, and Payday 2 will all be out by the end of that month, Kirby: Star Allies and Attack On Titan 2 will be out in March, Labo is out in April (though might not make an appearance in a Direct given the focus of that product), Donkey Kong: TF and Dark Souls are out in May, and Hyrule Warriors: DE and Mario Tennis Aces lack release dates beyond "Spring". On top of that, outside of Kirby: Battle Royale and Detective Pikachu (both March) there are no first-party titles confirmed for 3DS in the Spring/Summer window, so Nintendo might want to draw attention to Radiant Historia, The Alliance Alive and Shin Megami Tensei: Strange Journey Redux.
I'd also expect Nintendo will do more to flesh out what's coming in June and July - things like Sushi Striker for 3DS and Ys VIII for Switch need release dates. There are also a bunch of games scheduled for 2018 like Fire Emblem, Yoshi, Dragon Quest Heroes 1&2, Travis Strikes Back, Wolfenstein 2, and Octopath Traveler - some of which might get a 'summer' release confirmed (though not a specific release date). I'd also expect a handful of other announcements - some more third party releases, perhaps another first party title for Switch, and something for 3DS.
What I don't think we'll see any time soon includes Pokemon, Metroid Prime 4, Bayonetta 3, Valkyria Chronicles 4, Dragon Quest XI. I expect Prime 4 and Bayonetta 3 are 2019 titles - I think Pokemon will be being pushed for a 2018 release but might not make it, and I'd expect either an E3 reveal or a reveal a couple of weeks prior. Valkyria Chronicles 4 and Dragon Quest XI will likely be late 2018 releases in the West, and will probably be joined by some more first party titles confirmed at E3.