Presumably because neither of those sites are officially run by the Rust team, where as the Discord server and the forums are.
Maybe they could be added as "unofficial links"?
For a newbie all informations are welcome. Also this unofficial sources. Developers will actually use them because google finds answers there. And then they will be surprised why they didnt know about that sooner. Making a distinction between official and unofficial is good. But ignore them completely is not ok.