It doesnt matter to me. because I wont see him as Penguin. You can be greatest actor in world, yet be miss casted. And even if they try "redefine" Penguin as character it simply will be inferior to traditional one. Greatest thing about Batman's rogue gallery is they dont need to be redefined, remodernized or whatever.
Greatest trick in this case is believing this is somehow good casting because it's Reeve's interpretation of the character. And it's his vision. And yet just because it is, doesnt mean that's Penguin. Even if he is dressed as Penguin, talks as Penguin, has personality of Penguin, yet you dont believe it.