I had a similar situation 5 years ago. 2 x brothers and their wives made the Probate process absolutely impossible, high stress, and as difficult as possible, with extra costs (deliberately) being racked up by them and the eventual outcome of me not receiving the full amount of inheritance I probably should have done.
For background:
● the death 5 years ago was the death of our last surviving parent, and last surviving relative in the UK
● prior to the death of my father, there had already been 10 years of manipulation and gaslighting by one Sister in Law - to triangulate me from the rest of the family, and creation of an evil narcissistic alliance between those 2 x brothers and 2 x SILs.
Therefore I had always known / suspected that the death of our last parent (father) would be extremely difficult.
After Probate was finally settled (we had to continue to communicate during that period to get things done) I blocked all of them on everything - email, text, phone, WhatsApp, Facebook, everything.
For me, I found this to be necessary to protect myself from any further hurt, pain, gaslighting, and manipulation.
Do I regret going NC?
No, because in my circumstances I believe there was no other option.
However it has left me a very lonely adult orphan with no family support / family contacts. When I have to fill out "next of kin" on forms it causes me problems as I'm not married, and don't want to nominate the brother I would have (15 years ago) put down as my next of kin.
I also live more than 200 miles away from them which made the decision to block and delete them from my life much easier.