I do agree the long-term goal is to make her captain in the end; however, I think the later they do it the better. I think it really represents the end of her character arc.Whether it happens this year or next, Burnham will be commanding the Discovery. I predict at the end of this year because of the season's events.
To that end, I have to say that ending the show with the implication she goes on to have a long, decorated career as a Starfleet captain is way more interesting to me than "