Why is Nakamura not playing the US Championship?

At https://youtu.be/Y5Su4TQ-IlU

we can see he playing with his stepfather. 

I like to play like his stepfather, speaking loud and making things for fun:-)

At chess.com we can see a list of players.

https://www.chess.com/article/view/us-chess-championships#players

Hiraku is not listed.

List of Players
U.S. #1 GM Fabiano Caruana
U.S. #2 GM Wesley So
U.S. #3 GM Leinier Dominguez
U.S. #5 GM Sam Shankland
U.S. #6 GM Jeffery Xiong
U.S. #7 GM Ray Robson
U.S. #9 GM Sam Sevian
U.S. #10 GM Dariusz Swiercz
U.S. #11 GM Lazaro Bruzon
U.S. #13 GM Daniel Naroditsky
U.S. #18 GM Alex Lenderman
U.S. #28 GM John Burke

But the question is why he is not playing...

According to many replies from forum from the site above linked,
Hiraku Nakamura   is listed  in the Grand Swiss 2021 Tournment.
But it is currently scheduled to be running from 25 October to 8 November 2021

From wikipedia, we can see that Hiraku is on of the list of players at the Grand Swiss.
https://en.wikipedia.org/wiki/FIDE_Grand_Swiss_Tournament_2021

This both tounmentes are not in the same date.
Answer continues without answer.

Keep the arguments going. May the best man win!

You sparked a hot one here Daniel! Lol  

     Korchnoi just worked himself up to hate whoever was across the board. Karpov came in for the largest share of his abuse because he beat him twice in world championship matches. Korchnoi was reportedly so mad at Petrosian that he tried to get other players to denounce him even after he was dead.

     Probably the source of Korchnoi's mental problems was his experience of living through the siege of Lenningrad when a child. One of the most horrific episodes in World War II (hundreds of people dropping dead in the streets from cold and hunger every day, eating weeds, feral cats and dogs and rats, soup made from wallpaper paste, cutting off chunks of corpses to fend off starvation, regular bombings and artillery barrages) it left a psychological mark on everyone who experienced it. Victor only survived because other children in his family died and he could use their ration cards as well as his own.

You are incorrect.  Instead, all throughout previous human history, encyclopedic sources have been unreliable, because they are written by a small number of people with a shared viewpoint.  Wikipedia entries are formed by consensus, and mistaken claims will eventually get changed.

The Internet in general and Wikipedia specifically are actually killing the days of "the victor writes the history books".  You should be happy...these advances make it harder for dictators to rule the world .  

It doesn't matter in the end.  Use your abilities to discern information.  Wikipedia is a good source, and much better than most.  That is because of the ability for everyone to contribute to it, not in spite of it.

If you find an entry that looks like it's suspect, do more research.  You know, like anyone has to do when they try to find out anything.

Maybe he has the a chess version of the 'twisties'.........   

Congratulations!

This may be the most clueless thing I've ever seen written on the net.

Wikipedia has a controlling group of left-wing editors who exclude material that they don't agree with.  

The clearest example of this is the declaration of any news site that isn't left wing as a non-reliable source(RS), but there are many others.  The RS thing means that those sites can never be included in a politically contentious article.

Another conspiracy nut.  Shouldn't you guys be back in hiding now?

I trust the audience to judge whose argument is stronger.

Me too.  Better luck next time.

According to the FIDE calendar, there are the following world events:

There is only one classical & OTB event Naka can play in: Grand Swiss Riga