It’s interesting how there is this pre-war vibe going on but when you describe the actual predictions, it seems extremely unlikely. It feels more like a phenomenon created through the internet than actual pre-war anything.
The china thing is very out there - but I’d see them going for the push in Taiwan and things escalating there.
My main concern as a European is Russia. It is a historical truth that once a country goes through the process of starting a war economy it doesn’t usually dissolve or sit idle - conflict is going to happen there.
For America, watching from the outside, a civil war seems much more likely than direct war with china.
A war with China will do massive damage to the European and world economies, though, even if Europe stays entirely out of it. China more or less stops exporting (and importing); the economies of South Korea and Japan immediately contract 25% or more; Russia faces massive and nearly infinite demand for its resources from China; oil states in the Middle East would face massive price volatility followed by a collapse in demand and a loss of 50% of their government revenues; and every two bit nation in the world would decide now is the time to pursue revanchist feuds since everyone who could object is otherwise occupied.
For America, watching from the inside, this is highly unlikely. The worst case scenario for what's going on right now would be something more akin to the Troubles in Ireland than a full-on civil war for any number of reasons.
I don't know about parent's prediction regarding China but a major war between Israel and Iran is upcoming this year or early next year, which will involve United States by definition.
We are likely in pre-war era right now, dismissing it as "internet phenomenon" is shortsighted.