They do this, and still MONTHS with the playground being useless on Firefox because editing a message will completely wipe the message input box…
You have to “import” presets you had.
And now there is no “share a preset” to show issues.
Also:
The Chat Completions API does not support prompts, variables, reasoning summaries or the file search, web search, image generation, code interpreter, and MCP server tools. Switching will remove all reasoning items and any unsupported tools from the Playground.
Presets for chat completions are destroyed.
Just more attempts at lock-in, I guess.
History is also ruined. They load as “Responses” if you were to try to recover some function of remembering there.