Their carve-outs for safety (public interest) and legal are also valid exceptions in gdpr as well.
But they don't, they have the "30 days", but just after that they add "unless ....". So the time period is vague.
Since Anthropic is a US company the GDPR compliance claims would be dubious and open to litigation by entities like NOYB.
Everybody should just assume that they are lying about data retention and learning anyway.
They showed zero respect for intellectual property in the past and they will show zero respect now or in the future. A few thousand Euros/dollars in subscription doesn't matter when several trillions are in play (at least in their plans).
It's easy to catch a data leak if you have private data. You know what the model is supposed to not know, and you can just ask to see if it does. Yet I have not seen or heard of a single case of this being documented. As far as I can tell the labs do in fact respect the request to opt out of training.