If the West Coast ports are able to remain fluid, there is capacity in the system to handle some of this traffic (IIRC prior to the second Panama Canal opening the US Land Bridge was used for China->Europe shipping).
That said, the interior China->Europe rail routing is faster than using ships even in the best of times to the degree that there were were, prior to Russian invasion of Ukraine, premium China->Brazil services that were rail from China to western Europe (I forget which port) and then ship to Brazil to provide a faster than trans-Pacific, but cheaper than airfreight service for that market.