Bluntly, they can't. That genie is already out of the box for anything already available; and even going forward - Unless China itself blocks export, there's no realistic way to stop us from using a non-Chinese non-US mirror to grab them.
Realistically, hardware is the sole limiting factor for open-weight models, so restricting H200's is probably the closest we can come to a meaningful embargo. There's no practical way for most of us to run a model like Kimi K3 with almost 600GB (at BF16) of weights. Even using CPU offloading and/or multi-GPU sharding (if those are even possible for K3, I haven't looked at it in depth yet), the performance drop would give a throughput best measured in minutes or even hours per token, not particularly useful.
What this will accomplish is exactly what the OP quoted - It won't be possible to run these legally, so virtually all commercial use would be DOA. Joe Hobbyist couldn't care less though.