Not sure if you'll see this comment since it's been a week, but how did you find this out? Is 3.5 Pro officially cancelled internally? Are they only working on 4 Pro now?

Do labs come back from disasters like GDM’s 3.5 pretrain? I am thinking of Meta’s Llama 4. Meta is just now starting to be taken seriously again but they are definitely not at the frontier. And when I say “come back” I mean have an Opus 4.5 moment, which was really mind blowing for me at the time. Fable was a similar leap, just not as big.

Unless the company is going under, why not? Let's say Google releases Gemini Pro 4 tomorrow, and it's better than Fable and Sol; lots of people would switch over to it.

AI models are almost completely interchangeable, so the best/cheapest/fastest whatever will always have a market.

I agree we’d switch to it. I guess what I’m doubting is if a company can recover from that sort of stumble in the first place. And they might not want to either. They might think there’s more value somewhere else besides trying to get back to the absolute performance and capability frontier. Smaller models targeted to specific domains that large models would be too inefficient at no matter how large they get or how clever you are at distillation, for example.

OpenAI had such a disaster themselves before, GPT-4, so they replaced it with 4o.

gpt4.5 was also one such disaster for them iirc