Hope she is getting counseling. It’s not worth chewing the same shoe for years. Life is for living and you create your own reality by what you focus your attention on.
I have a feeling in your wife's case, he was ticked off about some silly little thing.
With my own father in law, however, I wish he HAD used the will as 'get-even time'. My brother in law raped his sisters and tried to rape my husband. He tortured them anytime he could get away with it until eventually mom and dad figured it out, and he was put away until he reached 18. When FIL split everything evenly, it was a real emotional issue for the siblings.
I was always Dad’s favorite & little Sister was Mom’s.
When he passed away a couple of years ago, my mother and sister looted his estate (co-executors). What I wound up with fit in a shoebox & is worth about $2 at a garage sale (and old baseball book & a NYY tie).
After being upset over it a long time, I realized IT’S JUST STUFF/money - and let it go.
I had the best Dad - 40 years of awesome memories & wouldn’t trade that for any amount of money or stuff.
Mom & Sis got it all, and are still miserable. (And it drives them nuts that I just don’t care)