You are purposefully misinterpreting his words to make your point. It would be history, just as Jackueline Kennedy’s death was history when it occurred after a long life and a second, happier, marriage. But it wouldn’t be historical, in the sense that JFK’s assassination was a pivotal moment in America’s history, not just his own or his family’s history. Princess Diana’s death was no, more or less history than jacqueline, but it was more historically significant in Britain due to her long mistreatment by the British press and that institutions willingness to pay for photo’s of her at obvious risk to her own safety. It was revealing of 2 important institutions, the press and the monarchy.
If she had died in a random traffic accident, it would have been less of a historical event, though no less tragic for her children, and other loved ones, as well as many Britians. No less that MLK’s mother’s death was probably a well known tragedy at the time in many black families (and probably some white families as well) but did not have the historical resonance that would lead us to teach it in school’s today.
The author’s overall point about women often being missing from history is completely accurate, but his primary example was was deeply misleading, and frankly partially derailed a discussion on an important subject. But heck, he got more clicks.