Short answer:Harari trained as a historian, but what he's writing today is more pop-anthropology and futurism than what a historian would call history.

Discussion:

In books like Sapiens, Harari's much more concerned with anthropology than history. Historians don't deal with "human nature", or indeed in the evolution or activities of humanity prior to written records for the most part.

In Homo Deus, which he describes as "A Brief History of Tomorrow" -- again, that's not history. For an historian to have a professional opinion about something, it has to have happened already, for the most part. As citizens we can say something about tomorrow, but that's not with a historian's tools.

Harari does have professional credentials as a historian, and _has_ written things which one would call history, for example

Harari, Yuval Noah. “The Concept of ‘Decisive Battles’ in World History.” Journal of World History, vol. 18, no. 3, 2007, pp. 251–266.

. . . which is a useful exploration of the relationship between battles and history, a long historiographic tradition.

Similarly, in his book

Renaissance Military Memoirs: War, History, and Identity, 1450–1600. (Warfare in History, number 18.)

. . . Harari does a good job looking at military memoirs with what a French historian might call "the history of mentalities". These works were well reviewed by academic historians in journals-- they're treated as "serious academic history" (albeit often more dependant on secondary than archival sources)

Harari has been pursuing a more popular audience for quite some time, producing interesting historical works like Special Operations in the Age of Chivalry [2007], also treated as an academic work, but with more than a little skepticism about his approach.

​

It is not easy to generalise from the varied kinds of military actions considered in this book. One of the arguments is that technological change, particularly the advent of gunpowder, had little impact; another is that special operations had a particular importance in siege warfare. Does the type of warfare analysed in this book deserve special treatment? Part of the case is that 'most medieval special operations have been forgotten', but not all the types of action discussed have sufficient in common to warrant being lumped together as a specific category. This is, however, a wide-ranging study, which sets medieval warfare in a novel perspective. The relevance of some of the films listed in the bibliography, such as Star Wars and Twelve Monkeys, is not immediately clear to this reviewer.

Prestwich, Michael. The English Historical Review, vol. 123, no. 503, 2008, pp. 1006–1007.

That last line "The relevance of some of the films listed in the bibliography, such as Star Wars and Twelve Monkeys, is not immediately clear to this reviewer", in the context of an academic review, should be understood as pretty damning . . .

So Harari began his journey away from academic history more than a decade ago, and his best sellers are really not "historical works" as seen by historians. A more pointed question for a book like Sapiens is "what do anthropologists think of it?" . . . and they've got their issues. His works are generally regarded as breezy and interesting for a lay reader, but you'll hear terms like "whig history"; still in the "story of everything" category he gets points for "not doing a bad job".

But you won't see him being cited much, either by historians or anthropologists, because on what subject is he a leading scholar who has done important original research?

You can compare perhaps to William McNeill who did similarly broad works relying substantially on secondary sources (Plagues and Peoples and especially The Pursuit of Power) which serve as better examples of an historian writing a very "big concept" work, accessible and popular with lay readers, which is also popular and influential with academic historians.