The title of this thread smacks of sensationalism on a British Tabloid-esque level - because Sakurai doesn't make a comment on the question, that gets interpreted as "may not be returning"? Last time I checked, every single game developer in the world does this; they reveal information about the game they're working on at a pace that they (and the publishers) see fit. If you asked Sakurai if Yoshi is coming back, he'd probably have given the same stock response, even though the idea of Yoshi not returning is absolutely absurd. Heck, if you asked Sakurai if Classic Mode is coming back he'd probably still give the same response. I think it'd be interesting to discuss whether or not the Stage Builder should return and how, but this article literally does not affect the likelihood of it returning in either a positive or negative way; all it really tells us is that Sakurai isn't willing to discuss the games features/modes yet (and why should he?).
That being said, I think a decent Stage Builder is long overdue, especially given that we've now got a touch screen to make stages on, which would make the whole process infinitely more intuitive - provided they actually put the effort in to improve the Stage Builder significantly (it always seemed to me like the Brawl Stage Builder was just testing the waters more than anything).