Well, I suppose they're saving the main Empire vs Republic story additions for new planets they plan to expand with in the future.
And as far as the Empire losing so much... well, they are the ones fated to lose the war in the end.
But it's too early to end the story with a landslide win.
And Like Palpatine said, "Once more, the Sith will rule the galaxy!" So it's not really settled.