If the government is tyrannical, they don't need an AI as an excuse. Lacking AI they can, and did, use the science, experts, god, devil, and a whole plethora of excuses since the dawn of the humans. Why would AI change anything there?
Only in the fairytale tyrannies that exist in the heads of Western nationalists. Real tyrannies rest on the labor of a large cadre professionals and managers, and constantly have to justify themselves or risk being overthrown. "AI," or any credential for that matter, has the purpose of isolating the decision from the decision makers. It's tyranny-laundering; tyranny in the passive voice.
But I'm sure that now I've triggered your cognitive dissonance and you will see me as an insane person.
No, the Experts who wrote the model are being deferred to as some kind of reliable expert. Because... they are exactly that.
You can make the argument that the models or the experts are wrong, but you're not providing any sort of argument for that.
I've spent most of my life deferring to the calendar to know when it will get cold for winter. It's obviously reasonable to defer to some systems. We are in fact quite capable of predicting all sorts of future events!
But the whole thing is just misdirection for their tyrannical desires. It's already working on you and you are wondering how it will ever work. Which is why I mentioned cognitive dissonance.