About 16% of China's exports in 2022 were to the USA. It would certainly be a significant hit, but to suggest there would no longer be adequate demand is unlikely to be true.

For example, Russian oil exports lost a lot of their direct importers, yet demand has not dropped significantly or in a way that is harmful for them. The volume of their exports has remained relatively constant, but the fraction of the total that different importing countries represent has changed. Even the price dip recovered.