The only thing that really makes me doubt that it's real is Yoshi's placement. I get that while you unlock characters the lineup changes, but that first line of characters see complete. I could never see Sakurai wedging a character from a different series in between characters from the same series. I mean say you start the game with the first line of characters being Mario, Luigi, Peach, Bowser, Yoshi, and Wario. As soon as you unlock Rosalina, do you really think she would be placed after Yoshi? Didn't Sakurai say Luigi was normally a secret character but decided to show him off early anyway? Luigi is still probably going to be unlockable yet his placement seems normal. Same goes for most of the other characters, except Shulk. His placement still doesn't make much sense, however I could see his changing as another charcter gets unlocked.
Just my thoughts on the matter.