**SOME** people will forget or try to deny... both Hiroshima and the Holocaust.... and various other purges, atrocities, ethnic cleansings, etc.
The world will not forget... there are too many passing it on and, like robomatic, will remind and show the images. Data is stored in so many places and formats that only asteroids and total nuclear war could interfere.... and then aliens in 100,000 years might find it.