Claude Fable 5 Isn't Nerfed. The Router Is Just Paranoid

BridgeBench's Fable 5 debugging score fell from 86.2 to 25.9 after reinstatement, but 9 of 12 TypeScript tasks were rerouted to Opus 4.8 by a safety classifier. Arena.AI's blind human-preference tests showed performance flat or improved in document and expert text categories. Anthropic acknowledged the classifier will produce false positives.