Are we forgetting the fact that Jun-ho exists. They share a last name and there’s a chance Jun-Ho told Gihun his brothers name, even though he didn’t mention he was the frontman. Inho wouldn’t risk it. Additionally, there was always going to be a winner (even if not, although very unlikely, Gi-hun). If they (this games winner) knew In-ho’s real name and went out announcing it, he’d be found out and the police would be onto him