I just checked and Random House has it listed as postponed indefinitely. Unless there’s a sudden big demand, or she either writes something else huge and creates more interest, or can get the rights back, I wouldn’t be holding out for it.

There’s a difference between a book that isn’t finished yet, and one that is written but the publishers don’t want to release it. It’s release date was meant to be November 21

Edit: 11th May 2021

Edit: those pesky American dates always get me