Anthropic is disabling Fable and Mythos at the request of the US government. I don’t think this is “our model is so good you can’t have it” marketing, because Anthropic seems annoyed. They blog that there is confusion about the capability even compared to other models:

We have reviewed a report that we believe is the basis of the government’s directive and validated that the level of capability displayed there is widely available from other models (including OpenAI’s GPT-5.5), and is used every day by the defenders who keep systems safe.

If you tell everyone your model is dangerous, it influences how people view it, whether significantly true or not.