I don't understand how LLMs can ask questions at a press conference.

I don't think an LLM can have secret human sources that provide them with confidential information anonymously. Not all news shows up on Twitter.

The primary source for most news is journalism.

Primary sources can and often are, very biased. Journalists are (supposed to be) doing fact checks and gathering multiple sources from all sides. Modern journalism is in a terrible state, but still important.

Imagine if all info about Facebook came from Facebook...