Well, chapter 11 was released in November, and it usually takes them several months to release a new one. I don't think they have chapter 12 ready yet, alhough it would be a pleasant surprise.
What we know for sure is that they intend to release a new dungeon during this spring, alongside a translation for the previous dungeons' storylines.
There should also be two New Semester banners in April, like the ones from previous years. They're banners that are released for the beginning of the school year, and they're full of new permanent units, which are usually characters that are relevant in the main story.
If LW were feeling daring, they could also release a new mountain event, like the Hot Spring Mountains or the Great Gendarme one. Those two came out in April-May: also, unlike other Housamo events, mountain events aren't linked to any specific holiday, so they can technically be released whenever they're needed.