This kind of innocence is when someone, generally of a younger age or uneducated, is not aware of jokes and references of historical events, and/or is surprised when they find out about it.
This can also be used to define someone that jokes about tragic historical events and/or support these "ideologies" without really knowing what they are about.
py: yo sav check this sus shit out
*shows sav a roblox group that fetishises the a*yan race*
sav: i don't understand
laz: yoooo what the fuck
py: sav, do not lose your intellectual historical innocence
laz: for your own good
sav: uhh what