Unclear Whether this changes fable's actual availability for any specific group of users, versus just restructuring how the check is computed, isn't clear from the evidence.
The logic that decides whether the "fable" voice model is available was reworked. It now checks a gate together with another condition earlier in the process, and for accounts not using multi-account routing, it branches on whether requests are routed "firstParty" (directly to Anthropic, always available) or through a "gateway" (routed through an intermediary, where availability is checked separately). This replaces the previous logic, which gated first-party availability differently and had separate fallback handling.
This changes how fable's availability is determined depending on how a user's requests are routed, though the finding doesn't specify what practical difference users will see.
Whether this changes fable's actual availability for any specific group of users, versus just restructuring how the check is computed, isn't…