Yup. If it wouldn't be possible, why bother and design the whole function in the first place? But indeed, it's very unlikely that you'll get your appealed pictures accepted.
According to the message that appears on top of the appeal page, it seems that a lot of photographers are using this function way too often. Some photographers probably appeal every single picture that gets rejected, just to have one very last opinion.
Anyway, since the appeal function was introduced, I've only used this function on two rejected shots. Needless to say that both of them got rejected by Johan as well
But anyway, 2 pictures out of a couple of hundred is not too much I think.