Even if they do actually follow through with it, it'll only be "assembly".
Also people calling for tariffs do not understand them, nor do they understand that; yes, China manufactures a shitload of iPhones, and Chinese companies make a small profit on doing so - a deal with Apple is very lucrative. But the majority of the profit made from selling an iPhone goes to Apple, aka an AMERICAN company. For iPhones sold ALL over the world.
Waaaa, I have to import my iPhone from China to America; the profits are still going back to America, perhaps every country that iPhones are sold in needs to put a tariff on nonlocally made products from a nonlocal company to match the absolute stupidity of Trump's logic.