This might be related to watermarking? And rare phrases would cost more tokens.
I am convinced that Anthropic the company is collectively suffering from AI psychosis and is basically a cult. My personal friends working there have gone from being able to discuss pros and cons of LLMs to saying things that Amodei says word for word to me. I only found out because after I talked to those friends, few days later I see Amodei tweet the same exact sentences.