Usually during the middle of the month are when January Directs happen. If you want my two cents, here's no doubt some "locks" for the Direct.
Persona 5 Switch - The rumors and track records are now starting to pop up out of nowhere as of very recent, which is at the least, unprecedented, unlike the Snake and Cloud situations. We could find out in a week or two, like with usual Atlus announcements, or in this one. Could be possible that we can just have a recap announcement in the Direct, if imminent news is upon us. Really, it's just a waiting game.
Final Fantasy Update - We need to know, at the very least, when Final Fantasy VII, IX, X + X-2 HD Remaster is coming out. It's been more than three months after it's original announcement and we haven't heard of anything since. They're pretty old to semi-old games and shouldn't need more than much effort, especially if we're talking about PS1 games. We might get an update on Final Fantasy Crystal Chronicles Remastered Edition and XII THE ZODIAC AGE amongst other things, but Final Fantasy overall is a must.
New Super Mario Bros. U Deluxe / Smash Ultimate Piranha Plant Reminder - Simple, gotta push that game hard like any other Mario game to get as much people to buy it. And as for Piranha Plant, the limited-time offer will end at the end of next month, so it's best to remind people about that, while at the same time market that deal to also sell more copies of Smash, too.
Fire Emblem: Three Houses / Metroid Prime 4 / Bayonetta 3 Official Reveal - I think this should go without saying. We haven't seen Fire Emblem since E3 2018, Bayonetta 3 since The Game Awards 2017, and Metroid Prime 4 since E3 2017. We've been out in the dark, and it seems as if Nintendo is ready to push other games outside of Smash, since we're now getting to be a couple of weeks to close to a month after Smash. Not to mention, these are big games for them, especially Metroid Prime 4. Gotta get them out.
That's about it, really.