OpenAI retired GPT-5.2 and migrated everyone to GPT-5.5.

OpenAI is consolidating its lineup, forcing all users onto GPT-5.5 amid rumors of an imminent GPT-5.6 (Tech Times). For API consumers this is a forced default change. If you pinned to 5.2 behavior in production, re-run your prompts and eval suites against 5.5 before the cutover to catch tool-calling or formatting regressions. Same lesson as the Fable shutdown, smaller blast radius: don't assume the model under your code stays put.