Just because we haven't seen characters yet does not mean they aren't in the story. They may not be introduced in Season 1, or there may be some 'surprise' about their appearance that they are saving for later. Or, despite having a name, they may play a minor role.
I recall when casting was announced for Peter Jackson's films, some people got upset over the 'absence' of Eomer, because Eowyn had been announced, but he had not. Naturally, Eomer was eventually cast and included in the project, and there is no reason to think that they ever intended to cut his character - he just wasn't announced with some of the other main cast.
I recall when casting was announced for Peter Jackson's films, some people got upset over the 'absence' of Eomer, because Eowyn had been announced, but he had not. Naturally, Eomer was eventually cast and included in the project, and there is no reason to think that they ever intended to cut his character - he just wasn't announced with some of the other main cast.