They've recently switched to opt-out instead. And even then, if you read the legalese they say "train frontier models". That would (probably) allow them to train a reward model or otherwise test/validate on your data / signals without breaking the agreement. There's a lot of signal in how you use something (e.g. accepted vs. rejected rate) that they can use without strictly including it in the dataset for training their LLMs.

They switched to opt out, with some extra dark patterns to convert people who already opted out into opting in.

I used to be less cynical, but I could see them not honoring that, legal or not. The real answer, regardless of how you feel about that conversation, is that Claude Code, not any model, is the product.