Are Mythos and Fable pure marketing?

I’ve been using LLMs for some time now and they’ve been getting better and better but the difference between each version has gotten smaller and smaller (it seems like to me).

Anthropic made Mythos super exclusive because it is “too powerful” and released a new generation of their AI models under, not just a new version, but under an entirely new name when it feels like just a new iteration.

Is this just marketing pure and simple?