What kind of bugs me about the trailer is the fact they revealed her as Chrom's daughter. In Fire Emblem: Awakening your not suppose to know that information until Chapter 13. I heard that they announced that she would be a clone character. It sort of makes her a spoiler clone character and that bothers me. I have no other problems with her as a character in smash though.
That's a fair statement, but it's the fact Lucina can be considered a spoiler character and a clone character. Shiek may have been a spoiler, but she was not a clone as far as I can tell. While Dr. Mario is a clone, but did not really spoil anything.