I mean, AWS Bedrock (with the exception of Fable) gives enterprises the same assurances (but again, with the exception of Fable, which is explicitly listed as requiring data egress [or exfil, depending on how you look at it] outside of your contractual AWS security boundary).
It gives you "assurances" that can be broken. They could still be clean-rooming your prompts like Anthropic does. The only way to be certain is if they don't have access to your data to begin with.
What do you mean by "clean-rooming your prompts?"