Are there any effective ways to add extra knowledge to an LLM, ways that are more than just demos or proofs of concept?

For example, could there be a site like HN with ten thousand contributors where the contributions are changes to an LLM rather than posts and comments?

One issue is that if contribution A contradicts contribution B, then on HN the contradiction presents no problem (i.e., two HN comments can and often do contradict each other just fine) whereas AFAICT the LLM will need to resolve the contradiction somehow to give coherent answers on the subject matter of the contributions A and B. Then again I suppose the LLM's answer could take the form, "opinions on [subject] vary, with some maintaining that . . . whereas others claim that . . ."