That plan is a massive government subsidy in exactly the same way. It's just that instead of direct payments, the subsidy is forcing the government to pay more

That plan is a massive government subsidy in exactly the same way. It's just that instead of direct payments, the subsidy is forcing the government to pay more for all its AI chip needs, because it is deliberately limiting the competition. So the US Government pays more for all of its AI chips and training and inference models under your plan than it does at present, and the size of that extra payment? That's your subsidy.