Meta's recent cadence for the Muse Spark large language model series explains the overwhelming 97% market-implied odds against a 1.4+ release by October 31. Version 1.3 launched publicly on September 2 with gains in long-horizon coding and agentic efficiency, followed by the open-weight Muse Spark Open on October 15 featuring 816 billion total parameters and a one-million-token context window. These updates align with Meta Superintelligence Labs' typical development cycles for major proprietary upgrades, which require extensive training, benchmarking, and infrastructure work. No official statements, API previews, or credible reporting have signaled an imminent 1.4 drop. Unexpected competitive pressure from rival labs or an accelerated internal milestone could still shift timelines before year-end.