I'm surprised they didn't do this the first time around. Like, a user says they forgot their password and you tell them they don't actually have an account, that's an information disclosure vulnerability. Not automatically falling back to Opus just lets the "attacker" know they are bumping against the guardrails and they need to try a different strategy.

It's Anthropic's product and they can do what they want, but my concern is what happens if Fable's product team decides that they can route 25% of traffic to Opus, bill it as Fable, and max their KPIs. That just doesn't sit right.