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.)