There is a third Partner Showcase for the Nintendo Direct Mini series was just announced today. This Nintendo Direct Mini: Partner Showcase is going to be live happening tomorrow at September 17th and it's going to be a live stream instead of a uploaded video like the previous two Partner Showcase videos. Since we know the first two Nintendo Direct Mini: Partner Showcase that we saw July and August were merely focus on 3rd Party titles than 1st Party titles from Nintendo themselves.
The stream starts at 7 A.M. Pacific Time tomorrow morning which is around 20 hours remaining (as of this post) as of right now.