Hidemaro Fujibayashi - Confirmed for BotW 2.
Tsubasa Sakaguchi - Last known work was Labo. He might have worked on Game Builder Garage, but it wasn’t as director (unless he’s been promoted).
Hiroshi Matsunaga - Last known work was Ring Fit Adventure. Given the success of the game, I wouldn’t be surprised if we get an expanded version (a la Wii Fit Plus) or a full-on sequel in the near future.
Kenta Kubo - I guess he counts as Brain Training was a collaboration with indieszero instead of just being outsourced. Might be a one-off director, hard to tell. Brain Training and Big Brain Academy are not handled by the same production groups and never have been. Expect Brain vs. Brain to be an EPD 10 project.
Hiromasa Shikata - Last known work was 1-2-Switch. I don’t know if we ever get confirmation that he became an official project lead in EPD 4.
Yusuke Amano - Almost definitely the director for Splatoon 3, if he hasn’t been promoted to co-producer.
Ryutaro Takahashi - Was last credited in Miitomo which has been dead for over three years. He’s not the only Tomodachi lead who’s been absent for a while. I think it’s only a matter of time until we see something from them. Similar to the Brain Training vs BBA comparisons, Tomodachi and Miitopia shouldn't be put under the same umbrella. Miitopia is handled by EPD 4 and has honestly more in common with Find Mii/StreetPass Quest on the 3DS.
Masami Yone - Was credited in Brain Training Switch (in an unknown capacity) for….some reason? He was the sound director for the original game on DS, but there were other sound staff credited like Minako Hamano who I imagine would have been supervising. Maybe it’s because the project began by porting the original game to Switch? Anyway, the assistant director and programming director for Rhythm Heaven Megamix have been uncredited since that game, with the latter being listed under “special thanks” in Brain Training.
Kenta Motokura - Working on the next big project from EPD 8. He was also a producer for 3D All-Stars and presumably 3D World + Bowser’s Fury. The Tokyo office was hiring for both a 3D and 2D Action Game back in Late 2019 and Summer 2020, respectively. It’s unknown if the 3D game was just Bowser’s Fury.
Shiro Mouri - Last known work was NSMBU Deluxe, while also providing development support for Mario Maker 2. The Kyoto office was hiring for a new 2D Action Game back in Late 2019, so I wouldn’t be surprised if he’s leading that project. It’s currently unknown if this is the same game mentioned above.
Yuji Kando - Recently credited in Pikmin 3 Deluxe as Chief Director, which was his first substantial credit since the original release on Wii U. Though it should be noted that the port was mostly outsourced to Eighting. With Shigefumi Hino moving onto Mario Maker after Pikmin 3, Kando is likely in charge of Pikmin 4. We’ve heard rumblings of the game getting a reboot at some point, which may explain the large gap.
Not even going to bother with EPD 9 (Mario Kart, ARMS, etc.), as the director situation isn’t really clear right now.
I should also mention that Mario Maker series director Yosuke Oshino left Nintendo shortly after the release of Mario Maker 2 to join The Pokemon Company, so who knows what’s happening with that series.