And even if some prototype device is, that doesn’t mean the production device will be, once things like heat and power usage have to really be accounted for.
It doesn’t even matter a lot if it does have really good graphics capability. Nvidia is good at that (though whether they’d price that where Nintendo wants is questionable). The question is what Nvidia can give in a CPU, because the only ARM CPU out there that’s actually interesting in terms of efficient per core performance is Apple.
That is not a gaming capable chip. It is a server chip where the entire value proposition is the core count and connectivity.
Nvidia doesn’t make anything and hasn’t shown any capability to make anything that isn’t a massive liability for gaming.