So I genuinely think that Amodei thought here that he was building a moat - set a very high bar for safety at exactly the line Anthropic but nobody else meets, and then declare anything less to be too unsafe to be allowed. That would put a permanent halt to open models, Chinese models and throw a significant barrier in front of competitors - if OpenAI is about to release something competitive with Mythos, they would have to immediately double back and implement at least equivalent safeguards. It might cost them months at the most critical juncture in Anthropic's history, when they are filing for IPO.
Having said this, I am sure they calculated in the possibility of their own model being restricted. They probably still see it as a win because it acts as a strong endorsement of them as the market leader and the model as the most powerful available model. So I think both things are true, but we are in the "plan B" scenario now rather than "plan A".