I'm glad you edited, because that was a little hard to follow.
No offense.
The school is thinking of things in terms of liability. As well they should.
YOU say that other listed parents want nothing to do with the kids, but the school can't just take your word for it. If they did, then they could be liable for failure to notify anyone besides yourself.
If you can't get a court order, type something up yourself saying something like,
"I, _____________, parent (or step-parent) of _________________, wish to be removed from any mailing, notification or emergency contact lists on file with the school effective this date. ________________"
Print two of them, so you have two originals that are signed, have an envelope addressed to the school ready, and mail one original to the school.
Keep the other original and make some copies for safe keeping.
If the other dad(s) won't do it, then without a court order or documentation of some kind, there will be griping about receiving things in the mail they don't want.
The school can't do anything about that.
Best wishes.