Reminder: This gets into a Partner Showcase because it's published by Koei Tecmo in Japan.
http://www.nintendoworldreport.com/news/71896/hyrule-warriors-age-of-imprisonment-gets-new-story-trailer-remains-undated
Although it was a Partner Showcase, there was a trailer for one first party title outside Japan.
Hyrule Warriors: Age of Imprisonment had a trailer in the showcase, showing off the traditional hack-and-slash combat with the Heroes and some of the Tears of the Kingdom-style building. A teaser for what may have been Fi was also shown.
The game is still slated for "winter", with more details promised in the future.