But surely transmitting information to actual SO is just as forbidden?

And if you're making an internal-only site, it doesn't really need to be name-brand SO.

Stack overflow was useful with a fairly sanitized search like “mysql error 1095”. Agentic LLMs do there best work when able to access your entire repository or network environment for context, which is impossible to sanitize. For a season, private environments will continue to be able to use SO. But as LLMs capture all the good questions and keep them private, public SO will become less and less relevant. It’s sad to see a resource of this class go.