1)
What do we learn from "va'Yimatzei Chasuv"?
1.
Torah Temimah citing Megilah 15b: It was written only now.] Shimshai (a scribe who hated Yisrael) erased (what Mordechai did), and Gavri'el rewrote it 1 .
2.
Chavrusah (Megilah 15b, citing Maharash Di Uzida): The Targum of 2:23 says that Esther told the king, and it was written in the name of Mordechai. Only now, the king heard that Mordechai saved him.
3.
Malbim: There, Mordechai's name was not erased. Refer to 6:1:4:1.
1
16a: If mortal writing for the merit of Yisrael is not erased, all the more so writing of Heaven is not erased!