So not familiar with the caselaw around work product, but if you use an API tool directly and not the different chat tools, the queries are not permanently cached for anyone to give up in the end.

So basically if you use any of the CLI tools, there is nothing for OpenAI, Anthropic, etc. to give the courts.

Online ChatGPT (especially the free version), are apparently cached by OpenAI on their servers. (I am not sure if Claude Desktop caches the conversations locally or in the cloud as well, read the fine print if it matters!)