This happened before with GPT-2 being touted as "too dangerous to release"[0] at the time by OpenAI. I don't think that means every model will be safe to release in the future, but nothing I've read about Mythos seems like it's going to be different this time.
It's going to be a slightly better Opus. Every model released by any provider since 4o has been a modest improvement but over-hyped. Opus 4.6 included.
I believe they are starting to split hairs and the primary lever left is adding compute.