[yongjik]

My understanding is that the official histories of Chinese dynasties were written by their successors and then passed down through generations largely intact, isn't it the case?

Of course it would be biased as the next dynasty has reason to justify the demise of its predecessor, but that's a far cry from saying that every dynasty "changed/destroyed historical records" to justify their policies.

cf. https://en.wikipedia.org/wiki/Twenty-Four_Histories