When you expunge something, it's as if it never existed. The author decided to expunge the entire paragraph that didn't fit the narrative.
Pro Tip 2/3
Often Negative
'Expunge' is usually used for removing things that are harmful or embarrassing. She sought to expunge the scandalous rumor from the small community.
Pro Tip 3/3
Metaphoric Use
It's often used metaphorically to describe the act of forgetting or disregarding something. After the argument, he tried to expunge the hurtful words from his memory.