Their CEO is on record as saying this. You may think he's lying, but that's just your opinion; given the pricing and how it stacks relative to the pricing of inference providers of comparable open source models (who are certainly charging above cost!), I am inclined to believe Anthropic on this.
Maybe because Anthropic are trying to get to an IPO and everything is securities fraud?
If their CEO was just flapping his mouth without any other comparable baseline, it'd probably be different. But as the GP points out, open-weight model providers are charging comparable rates and very likely have positive profit margins. That would imply that with API pricing tokens are sold at above cost.
That cost may well be "inference only", so excludes everything apart from hardware and power. Whether that's enough to cover the enormous training costs and other overheads is a different question.
He just told you. Because overwhelming public evidence supports the claim. Especially the pricing of open weight model inference. Why do you allow a prejudice to overshadow evidence?