Miyamoto confirmed it was in development as recent as 2017.

i don't know what to expect other than whats announced. It would be nice if there were one game outside of zelda to really get me excited. I'm more of a AAA open world gamer. Xenoblade might be tight but i want something new. metroid won't be out next year. Right now my highest hope lies within pit being a featured playable character in gods and monsters from ubisoft. I haven't played a really good 3rd person shooter in a long time. It'd be nice if we could get a 3rd person star fox game. Like star fox adventure meets army of two meets ghost recon wildlands. the only 1st party game i got in 2019 was luigi's mansion. Not a huge deal since i was playing smash for most of the beginning of 2019, but seriously it'd be nice to get 2 AAA tent pole titles a year.

The best chance you have in 2020 is the 3D Mario team churning out another open sandbox game; other than that, there's the small potential for a 2nd party collaboration or a 3rd party using a Nintendo IP.  Speaking of Star Fox, you could always hope that the Starlink team at Ubisoft Toronto is making a Star Fox game since, despite low overall sales for Starlink, it was a productive creative collaboration between the two companies.

sounds about right. Hopefully biomutant actually does come to switch and is really good.

Oh my goodness. I never thought of that, now I can't stop wanting it. It seems totally possible too.