Restore 5.1 in ChatGPT: Replacement Is Not Migration - OpenAI Is Breaking Power-User Trust

Welcome to the dev Community! @chenshiwen0429 Thanks for sharing your feedback. I understand your concerns around GPT-5.1 and the impact model transitions can have on established workflows. GPT-5.1 models were retired on March 11, 2026, and conversations were migrated to newer model versions. OpenAI periodically updates and retires older models as newer generations become available, with the goal of advancing model capabilities and improving the overall experience. That said, we appreciate hearing how these changes affect real-world workflows, especially from long-term power users. I'll make sure your feedback is passed along to the team for consideration. Thanks for taking the time to share your perspective. ~ Smith