Actually, you said “If procreation is a human right…” (emphasis added) and the rest of your argument stemmed from that. It isn’t firmly established that procreation is a fundamental right, or at least it isn’t enshrined in the U.S. constitution. Besides, we’re arguing about different things. The issue isn’t directly about preventing the guy from reproducing, it’s revoking his probation on past offenses if he rather stupidly makes his situation worse. Following your libel analogy, it’s as though a person was told by a court “We’re slapping a judgement of $1 million on you, but we’ll hold it in abeyance as long as you stop libeling people. If you publish another story about Billy Graham and the altar boys, it’s clear you’re not able or interested in changing your ways, so you’ll have to pay the fine in full.”
In any case, discouraging further procreation until and unless this guy gets his act together is pretty mild as punishments go. It’s not nearly as much of a hassle as house arrest.
Well, there’s another of those tricky “ifs”. There are numerous rights that can be taken away from convicts. Even if we grant that procreation is one of them, why can’t it join protections against search & seizure and the vote and other rights commonly denied prisoners?