

Yes, but the other countries that buy from elsewhere will want their normal amounts too.
Can other food producers increase their production while the US spirals down? Nobody really knows, we are in shock due to both global warming and the war in Ukraine. And the US is a really major food exporter.
Can people make do with less food? Probably, but it’s not trivial.
Anyway, China’s tariffs are completely self-imposed. They can cut them at any time.
If the US manages to reduce their imports, what will probably happen is that the rest of the world will cut the more optional consumption from there so that they can keep buying the food. What means that US industry will suffer.
But your first feeling that sellers and buyers will redistribute who they deal with is probably correct too. Anyway, the tariffs shouldn’t have an immediate effect of changing how much food moves around, but nobody knows what domino pieces they will hit on the fall.
On the very short term, China is tariffing stuff that hurts. What means they are serious about not buying from the US and will pay extra for the privilege. And yes, also means somebody else will probably take their place.