In the original timeline, Anne Frank didn’t have a diary, but eventually, the day came when people forgot.
Determined to set things right, CERN sent back in time one man with a single mission: Deliver a modern ball point pen to a girl who can write write about her struggles.
That’s why Anne Frank’s diary is written in ink that didn’t exist yet when she was alive. You can’t just write her off, that’s speculative nonsense!