Yerm on 03 July 2018
Nintendo Directs generally release every 3 - 4 months, with some noticeable trends. there is usually a Direct at the end of the year, (late October, early November) and they have done a few on April 1st.
but thats a bit of a weird question since they dont usually address games in terms of media attention or controversy, even the likes of Federation Force or Animal Crossing: Amiibo Festival. if they have something new to show off, and it will release within the next year, they will show it in a Nintendo Direct. i suppose if they had to, it would be at the top of their list when scripting the direct, but it wouldnt really be given any more dedicated time than any other game being showed off when making the video
