Google’s repeated delays with the long-teased Gemini 3.5 Pro, combined with a clear pivot toward faster Flash iterations and early Gemini 4 work, underpin the market’s 97.7% implied probability of no Pro-model release by September 30. The most recent flagship Pro variant arrived in February 2026, after which Google shifted resources to shipping Gemini 3.8 Flash in early September and placed Gemini 4 in post-training refinement, with DeepMind leadership stating only that an early version could arrive “as soon as possible” before year-end. No official announcements, API changelog entries, or partner briefings have signaled an imminent Pro launch in the final days of September. A last-minute surprise drop or accelerated Gemini 4 preview could still alter the outcome, though historical timeline slippage and the current development cadence make such a move improbable.