Yeah, you can't ban files. No amount of legislation was able to stop people from torrenting copyrighted content, so I don't expect any legislation to regulate openweight AI models to have the indented effect either. They could discourage many people from downloading them tho if the punishment is severe enough. But this wouldn't discourage bad actors as they most likely would know or do research about the protective measures they need to setup to avoid getting caught (trusted no log VPNs, tools to prevent deep packet inspection, etc)
Besides, anyone would still be able to use openweight models (almost) unbothered by just using a non-US inference provider that also provides access to Western models so you have some plausible deniability. Also anyone would still be able to run abliterated models using non-US (or whatever country that would collaborate to enforce this madness) inference providers