The opposite of “approbation” — a fancy synonym for “approval” — is the word, “disapprobation,” which naturally means disapproval.
It would stand to reason, therefore, that the opposite of “opprobrium” — harsh criticism or censure — would be “disopprobrium.”
Unh-unh.
No such word.
All of which leaves me pleasantly mayed** . . . 🙂
**The opposite of “dismayed.”