One that I can think of off the top of my head is The Mandalorian: An Original Novel by Adam Christopher.

It was announced in mid 2020 and slated for December of that year. Then it was pushed to almost a year later, in November of 21. But then in March of 21 it was cancelled entirely.

I have wondered if the book focused on Cara Dune in some capacity, and since she was fired from the show they shelved the book instead of rewriting.