This is the first low-key, silent feature rollout, treated like "just another software update", with no hype or buzz beforehand. Prior to this point, every other feature release was pumped for weeks or even months with "leaks" from insiders and deliberately getting people amped. I don't know if OpenAI changed marketing tactics, or if they're in a new chapter in some book, but this is a radical shift from what they were doing before.
I feel like the rollout was a bit rushed. Benchmarks for 5.1 came out a day after the launch. New models weren't immediately available through the API. And then there's 5-Codex-Mini which was deprecated only six days later by 5.1-Codex-Mini. Wondering if Gemini 3 forced their hand here?