He did announce that he became Muslim.
The Prophet (s) forgave him in the sense that he didn’t punish him for killing Hamza (a). But he asked him not to come in his presence for he didn’t want to see his face, and he asked him to leave Medina because his Islam was superficial not real. Wahshi didn’t have the success to genuinely repent. He was among the hypocrite Muslims.
He would drink and he died drinking.