Sure, but if Nvidia “ceased to exist,” the fabs could keep manufacturing the same chips. So at least in the near-term, the world wouldn’t change much. Whereas if TSMC “ceased to exist” then there would be an immediate worldwide chip shortage.
That's not how it works. They're Nvidia's chips. Would Foxconn go on and keep making iphones if Apple whatevered?
If someone wanted to buy them from Foxconn, then probably…
not without purchasing the license or additional contracts. its nvidia IP.
And if nvidia vanished, there would be no one to care about the IP violation.