Does/did Buddhism assert that everything that is/was important to know about the world is/was already known? Harari (2011) claims:


  Premodern traditions of knowledge such as Islam, Christianity, Buddhism and Confucianism asserted that everything that is important to know about the world was already known.


From my limited understanding of Buddhism, the above seems false of Buddhism.

I was hoping an expert on Buddhism could give a more definite explanation as to whether the above statement has any truth. (Restrict attention to the bit about Buddhism.)
The buddha said that some people found the truth before him, but of coure most people didn't 


  “In the same way, I had now arrived at the ancient way of the noble
  ones, the ancient path of the noble ones, the ancient way trodden by
  the noble ones, along which passed the noble ones of ancient times,
  and which I should now follow, namely this Noble Eightfold Path: right
  view, right aim, right speech, right action, right livelihood, right
  skilful means (effort), right mindfulness, right concentration.


https://suttacentral.net/sa287/en/choong