Have you bothered to do any sort of comparison as to how similar attacks are reported? At a quick glance, I see nothing on George W Bush's wiki page[0] about the 2002 consulate attack in Kolkata[1], for example.
[0]: https://en.wikipedia.org/wiki/George_W._Bush
[1]: https://en.wikipedia.org/wiki/2002_attack_on_American_cultur...
I have trouble believing anyone with the remotest knowledge of US politics is unaware of the scandal, but https://www.britannica.com/event/2012-Benghazi-attacks . 'Reactions and investigation' has the information you apparently missed all these years.
https://www.wsj.com/articles/SB10001424052970204712904578090... - "What we now know—and still don't—about President Obama's 9/11." is pretty good too.
Not that it's necessarily wrong for it to not be listed there, though. The article on GWB is about him and what he did as president - it isn't meant to be a complete history of the United States between 2001 and 2009.