Where the TOS allows them to, I would assume they are (and they aren't trade secrets anymore since reasonable measures weren't taken to protect them). Where the TOS forbids them from doing so - I'd generally assume the reputational risk is not worth the marginal value that could be extracted from the IP and trade secrets. Especially for companies with huge other businesses like Google. I'd worry more about Anthropic and OpenAI just because there's not this other huge billion dollar business that relies on trust. If I had trade secrets worth billions where money could easily be extracted from them (I'm thinking something like a hedgefunds current trading strategy) the trust wouldn't extend that far even for Google.

I also find OpenAI's past business dealings suspect (with regards to effectively stealing value from the public non-profit and transferring it into a privately owned company) which makes me trust them less than Anthropic.

I'd assume the NSA has access to anything they are interested in that you send to a US company.