Sure, some trust is required that they aren't breaking their own terms of service (which legally enforces that they won't train on your data), but the same is true of every company/service you deal with (AWS, Google, your CRM etc). Their entire business model depends on enterprises trusting them.
But if you're going to take your distrust that far then the issue is that they have your data at all, not that they are telling you that they will retain it for 30 days.
We’ve repeatedly watched that trust abused and exploited in these last few years, in both public and private sectors (including specifically in this field). I broadly agree with you, but I tend to think it’s a finite resource that’s eroding rapidly just now.
If that is the question. Those customers anyway won't be using any LLM or cloud services in first place. If you are a jornalist investigating nations, stay away from everything.
If you don't trust them, then no policy is enough. Technically everything you send to the model could be stored by them. Personally I do worry about that especially as an average consumer not an enterprise, no one is looking out for us and we don't get any guarantees. But enterprises will get the right treatment because they would find out and sue Anthropic if they lied.
I mean, if we're assuming they're just willing to lie and violate their own TOS then how could you ever be comfortable with them regardless of this 30 day period (or really any online service)? This seems like a bit of a silly take.