What makes you think that? "it reads like a Claude Mythos model card that was hastily edited to be an Opus 4.7 model card"

There are more mentions of Mythos than 4.6. Mythos results are nearly everywhere, and vastly exceed 4.7's capacity in almost every case. There are sections that report only research on Mythos, none on 4.7. E.g. user surveys about how beneficial Mythos is internally at Anthropic.