Ok Disney, here's the deal.
There has never been a better time to use Starkiller then now.
Why? Because as of now, the single most pupular character on screen is by coincidence a padawan of Anakin Skywalker, and that would make the secret apprentice of Darth Vader the perfect foil. Not to mention, that the little girl had such a power creap, that he would actually be a worthy opponent at this point.