It is currently Spring, but I can speculate what Nintendo plans and what game announcements may appear when E3 draws near.
1) Splatoon 3: Since the new game's reveal and coming soon next year, The Squid Research Lab will give the breakdown of this new landscape, new weapons and updated turf wars in the post apocalyptic world. Maybe a Global Testfire announcement in late 2021. (Thanks Team Chaos, you made this world setting happen.)
2) Smash Reveal(s)?: We already know that Smash reveals isn't far behind as Smash is one the BIGGEST HYPE a lot of people are expecting. Who is Challenger 10 and 11? Sakurai either reveals one again or both with discussion about Ultimate's DLC development.
3) Finally news for Metroid Prime 4 and/or Bayonetta 3?: These two projects have been under the radar with no updates on the game's progress. Maybe the team is ready to give the fans a sneak peak.
4) new games: Laying out the next games in store for people Triple AAA and Indie games.