The part that I think may have some credence is that it may be a way to prop up huge profit margins that may persist for longer than they would otherwise in lieu of further commoditization and competition.

If NVIDIA has a stake in the company, they are less likely to do something like start brewing inference chips in house with the help of the foundry partner and a provider of vanilla chip designs. The company also gets a huge cash injection that is somewhat contingent on not doing that, and hey, they have a fresh pile of cash for cutting edge chips so whatever, right? My first thought was that these deals had more to do with that than anything else.

That aspect may end up being a bit illusory in the end. But then again, Nvidia has been proven to be quite skilled at building out and defending their ecosystem, sometimes through ruthless means, so maybe it persists (and I'm not sure that's a good thing). China certainly isn't a threat to throw a wrench in this situation... the entire US geopolitical complex will ensure that is the case.