I don’t know if this will help but: An annulment doesn’t say the sacrament was “invalid” (or in any way defective) it says it never occured in the first place. The marriage never occured in the eyes of God.
This is how it’s different than a “simple” divorce. A divorce is man saying (or trying to say but failing miserably), “This marriage no longer exists. It’s terminated.”
No one has the power to do that. “What God has joined no man can separate”. This is always true.
So the good Father here is in no way lessening the sacramental vow and bond. It never existed in the first place for him, or his wife.
Does this make the children bastards in the church which annulled the parents marriage?