If true and I do not doubt it, then Father John is a moron. Why did your family not just go to another Catholic church? Father John did not excommunicate your family, he simply exerted a power trip. No man will ever stop me from pursuing my faith.
ALL of the churches, Catholic churches, in our area followed the same practice. It was common practice across the nation.
SOME churches, I've discovered since being an adult, turned a blind eye to separated/divorced status. But many, if not most, did not. Not back in the 50's and 60's.
Then they lost so many people they changed their policy. But not in time for my family, which needed the church more than we ever needed it.