Some of the regulation they have previously supported may impact open weight models. Example: are Chinese companies likely to comply with the testing and reporting requirements? And even if they are, the hundreds of remixers are almost certainly not.

Caveat being such regulation may not apply depending on... size of model? Income of originating company? Income of remix creator? It's in flux, but they have an incentive to deter potential future competitors.

The given article from Anthropic only limits scope to and demonstrates with open weights models. The push against banning open models is an aggregate they continuously make, very publicly, using these kinds of things as examples for why it's needed.