GPT-4o Fully Retired from ChatGPT; GPT-5.2 Becomes Primary Model Amid 20,000-Signature Petition

OpenAI completed the retirement of GPT-4o from all ChatGPT plans (Business, Enterprise, Edu) on April 3, 2026, with GPT-5.2 now serving as the primary production model; deprecated models remain accessible via the API. The move triggered over 20,000 signatures on a petition to restore GPT-4o and widespread developer frustration, referencing OpenAI's pattern of repeated retirement and reinstatement cycles — including the August 2025 reversal. Developer sentiment is visibly shifting, with community threads comparing Claude Opus 4.6's agent capabilities favorably against GPT-5.2.