He certainly can, but that doesn't mean he can't suffer any consequences. Free Speech means he won't be arrested by the government. It doesn't protect him from being fired by his employer, or from being ostracized by society for his beliefs.
Case in point, F Champ is free to express whatever garbage opinions he might have. He's not in jail right now, he's not facing charges, he's not being held fiscally liable for anything. But if his employer decides that he's not the type of public figure that they want to associate with, and if Capcom decides that he's not someone they want to associate their brand with, they're well within their rights to ban him from their events.