I don't think Sakurai is involved with the new Kirby game. I could be wrong, I couldn't find any articles though mentioning it.

Well, I guess Shinya Kumazaki, would be the guy, who technically took Sakurai's spot. Or at least he's the series current director.

All that being said, I am also interested in what Sakurai does next. I am honestly a little tired of him being restricted to Smash. I would really like to see his imagination flow, brand new characters, lore, ya know, brand new IP. I know Smash has a lot of his own twist to it, but it's still restricted to established Nintendo characters only.

Kid Icaris Uprising is the best Star Fox game ever made and I want a sequel to it! Also the best use of 3d mode I ever had on the 3ds!

Well deserved. significant portion of my favorite games were developed by Sakurai. Would love a sequel to either Kid Icarus Uprising or Kirby Air Ride, but doubtful they're in the cards.

Meteos 2 here we go

Would love to see something other than Smash. Smash Ultimate DLC/development (minus minor updates in the future) seemed to end right around October 2021 with Sora released. While it's Sakurai's choice, I'd hate to think he's already in serious pre-production of Smash 6 already.
Another Kid Icarus game, other revived Nintendo IP, or something new would be cool.
And on the topic of Sakurai's achievements and career, it would be nice for someone else to helm the next Smash. Sakurai can still be a producer or even just a consultant.

I just hope he is having a nice long rest after smash ultimate.
Sounds like he put a lot into that game and deserves a break for a while now that the work is done