SemiAnalysis: Anthropic has set strict classifiers for Mythos due to regulatory pressure; Mythos 2 has completed training but has not been released

According to the SemiAnalysis podcast, Anthropic has set extremely strict classifiers for the public version of its flagship model Mythos, called Fable, due to regulatory pressure. Users attempting specific actions will be immediately downgraded to the Opus model, and conversations cannot be reverted. Dylan Patel, founder of SemiAnalysis, stated that the classifier restrictions are "too harsh," and even internal employees cannot complete routine tasks with it.

The podcast mentioned that the Mythos model completed training as early as February, but Anthropic did not release it under the name Fable until May. Jordan stated in the discussion that, to his knowledge, Mythos 2 has completed training but has not been released, and the internal R&D team is believed to still be iterating. Analysts believe that Anthropic's previous long-standing calls for regulation have now resulted in regulatory measures that limit the release pace of its own models. Similarly, OpenAI is also delaying the public release of its next-generation models, but internal training is still progressing, and the capability gap between internal models and public models may continue to widen.